While what is now called inculturation did not begin until forty years ago, its theory and praxis have recently become prominent in Catholic missiology. The debate is especially heated in Asia, where inculturation seems more complex and challenging. The author illustrates the challenges, difficulties, successes and failures of the long process in China. He also mentions the phenomenon of Cultural Christians in Mainland China, which has renewed hopes for an inculturated Christianity, or more specifically, for an inculturated theology. The task of elaborating a Sino-theology presents a major theological challenge to Christian theological and ecclesial communities in Hong Kong, and to the theological world at large.