This study forms part of a wider comparative research project investigating the mechanisms and outcomes of school-based curriculum (SBC) development in kindergartens between the two neighbouring cities of Hong Kong and Shenzhen, under the umbrella of 'one country, two systems'. This comparison will help to clarify how sociocultural contexts may affect early childhood curriculum (ECC) innovations by comparing the kindergartens of socialist and capitalist China. Data are presented from qualitative case studies of four kindergartens--two in each city--corresponding to the three levels of curriculum analysis and comparison: intended curriculum, implemented curriculum and curriculum ideology. Comparative analyses revealed that the SBCs of the four cases were different but all tended to balance and integrate diverse approaches in terms of curricular and pedagogical practices. The commonalities of SBCs in Hong Kong and Shenzhen kindergartens were due to shared cultural values, propelled by both 'modernization' and Chinese traditions, while the unique characteristics of SBC practices in each society were shaped by different social contexts. The educational philosophy of progressivism has greatly influenced ECC innovations in the Chinese kindergartens to varying degrees and in different ways. Implications of this comparative study are also presented for future research and practice.