Sustainability is a process or state that can be maintained for a long time [6]. Sustainability in ECE tends to focus on the provision of accessible, flexible, affordable, and high-quality care and education, and, more generally, on how sustainable the ECE “system” is over time [7,8,9]. However, there is no unified definition of the sustainability of ECE, which is generally understood as the perfection and permanence of a series of systems and mechanisms to ensure the development of ECE in the context of achieving high-quality development of education [10,11]. In other words, the sustainability of ECE refers to the harmony, efficiency, and long-term nature of promoting the high-quality development of ECE. In addition, previous studies found that the factors affecting the sustainability of ECE can be roughly divided into three aspects: micro-, meso-, and macro-.

First, the macro-level focuses on the sustainability of policy support for ECE. The term sustainability is now widely used in ECE policy [12], which refers to whether the policy itself could be sustainable and sustain the development of ECE [13,14]. An effective, sustainable education policy should refresh and innovate with the contemporary economic and social needs over time [15]. Sustainable preschool policy depends on various factors, such as the sustainability of the policy provision per se over time, the continued financial input of the government, and the perspectives of key stakeholders in the policy [15,16].

Second, the meso-level focuses on the sustainability of ECE management. ECE management plays an important role in leading, organising, and monitoring the development of ECE, and its premise is to promote the healthy and sustainable development of ECE [17,18,19]. The construction of the ECE management system should take the public’s diverse needs at its core, and the government, market, and society should make full use of their respective advantages to continue to solve the problems [20,21].

Finally, the micro-level focuses on the sustainability of the environmental ecology of ECE. Raban & Kilderry [22] suggested that what is usually missing from the dialogue on sustainability is a reference to environmental sustainability, where the environmental impact of ECE infrastructure, duplication of resources, and so on would be considered. In addition to the sustainability of the environment ecology, the sustainability of education ecology is also important. As an important part of ECE, it differs over regions, cultures, and times [23]. Therefore, ecological sustainability in ECE includes a sustainable environmental and educational ecology [24].

In general, sustainability is the core proposition of ECE development. However, previous studies have addressed the sustainability of ECE primarily by analysing past and present government ECE policies, strategies, and their impacts, and predictably examining whether they could be economically and socially sustainable [17,19]. On the other hand, no research has developed relevant measures to measure the sustainability of ECE from the stakeholders’ perspectives, as evaluation requires the participation of stakeholders [25,26]. Therefore, based on previous research conclusions and combined with the development status of China’s ECE, this study has proposed a set of core indicators that affect the development of ECE and then explored the sustainability of ECE from Chinese teachers’ perspectives, aiming to better promote the high-quality development of ECE.

The most important stakeholders in evaluating the sustainability of ECE in this study should be teachers. However, it is not until the fourth generation of evaluation that the stakeholder viewpoint comes into people’s sight. The fourth generation of evaluation theory determines the stakeholder as an important element of evaluation [27]. Furthermore, in the relevant policy texts of ECE in China, such as the Measures for the Supervision and Evaluation of Universal Preschool Education in County Areas [28], it is also mentioned that the participation of stakeholders is an important indicator of ECE evaluation, and multiple parties should be encouraged to participate in the evaluation, and third-party evaluation should be actively introduced. According to the stakeholder theory, kindergarten teachers are the key perceivers of ECE development, have direct experience in the provision of ECE services and the development of kindergartens, and play a crucial role in the development of ECE. Reviewing existing studies, we can find that teachers’ participation in evaluation is usually carried out in the way of teachers’ perception. The evaluation is roughly carried out from the following perspectives: (1) teachers’ perception of educational evaluation tools. For instance, teachers’ perception of the practice and implementation of “continuous assessment”, a comprehensive, systematic, cumulative, and guiding child assessment tool [29,30]; (2) investigated teachers’ perceptions of national/state programs, including evaluations of the relevant national programs, perceptions of the evaluation process the teachers participated in [31]; improved by evaluating teachers’ perceptions of interstate programs and their implementation effects [32]; (3) the perception of the status of educational practice. In addition, teachers play an important role in assessing creativity in preschool [33] and perceptions of preschool readiness [34].

In addition, there are multiple factors influencing teachers’ perception and evaluation. Previous studies have shown that a person’s intention to act is shaped by personal, social, and educational backgrounds [35,36]. Teachers construct their own knowledge, skills, and job-related knowledge system, which is important for their perception of policy [37]. Teaching experience, socioeconomic status and ethnicity are closely related to teachers’ perception of policies and evaluation of students [38]. At the school level, trust and support in school leadership significantly impact teachers’ perception of policies [39]. Yan et al. [40] suggested that personal factors (e.g., education and training, attitudes, skills) and contextual factors (e.g., school environment, external policies, working conditions) can influence teachers’ evaluation practices. All of these studies are based on western background. In addition, some Chinese studies have found that age, teaching age, geographical area, and school grade are important factors affecting teacher perception and evaluation [41,42]. From previous studies, it can be found that most of the factors affecting teachers’ perception come from subjective, school, and social environments. However, under the unique social context of China, there are still many influencing factors that can be explored, such as teachers’ professional titles. Therefore, this study assumes that teachers’ age, years of teaching experience, professional titles, and the quality grade, type, and location of their kindergartens affect Chinese teachers’ perception and evaluation.

To sum up, as the gatekeeper of ECE, teachers’ views are very important. However, there are few studies on ECE programmes in China from the perspective of teachers’ perception, and most of them are based on the evaluation of ECE from the parents‘ perspective [2,43,44]. Moreover, teacher evaluation is related to the sustainable development of ECE, the government‘s policy-making, and whether the needs of stakeholders can be met. Therefore, the evaluation of the sustainability of ECE should attach importance to teachers’ participation. Further, to reveal potential differences in teachers’ evaluation of the sustainability of ECE in a better way, this study employed a person-centred approach (latent profile analysis) that differs from the variable-centred approach, which can uncover more “unobserved” subgroups in large heterogeneous populations [45].