China's 'Conversion of Cropland to Forest Program' (CCFP) is one of the world's largest national 'Payment for Ecosystem Services' (PES) programs, with over 32 million rural households enrolled and 28 million ha converted to forest since 1999. Given the scale of the program and emerging interest in forest landscape restoration, the structure and function of implementation models is of interest. This study is based on key informant interviews tracing the structure and interactions among institutions for implementation of the CCFP from central government to provincial and sub-provincial scales in Yunnan Province. Data are used to analyze implementation arrangements for program planning, implementation and monitoring, and to identify features ensuring conditionality of PES payments. To assess the degree of voluntarism in enrolment, the study employs data from 87 household-level interviews in four southwestern provinces. Findings indicate that the CCFP system is designed to fulfil expectations of PES programs in terms of conditionality and voluntary participation on the side of ecosystem service sellers.