Widespread concerns about the quality of early childhood education and care (ECEC), and the desire for better child outcomes, have led to a focus on improving teachers’ professional development (PD) as a cost-effective means of improving ECEC quality. However, most randomized controlled trials (RCTs) of PD programs have taken place in areas with advanced educational systems. This study aims to fill this research gap by adapting (both educationally and culturally) an evidence-based PD program entitled “Leadership for Learning” in the Chinese context where there is a paucity of effective PD programs. Ninety-five classrooms, 202 teachers, and 547 children (3–5 years old) from 24 kindergartens (12 control, 12 intervention) participated in this RCT program which was designed to improve teachers’ teaching quality and child development. The results of the multilevel modeling indicated that the intervention was positively predictive of classroom quality and child developmental outcomes in literacy and executive function skills. As one of the first studies exploring PD effectiveness in China, this study has several meaningful implications for PD intervention as well as cross-cultural research. (PsycInfo Database Record (c) 2024 APA, all rights reserved) (Source: journal abstract)