Li Zhizao (d. 1630) was one of the most famous early Chinese Roman Catholics intimately associated with Matteo Ricci (1552-1610), the founder of the Jesuit mission in China. In spite of his fame, Li's religious experience has not so far been adequately investigated. To understand this crucially important aspect of his life and the related early modern East-West intellectual interaction, this article looks closely into ques­tions about his conspicuously late formal entry into the Church, the peculiar circum­stances of his agreement to receive baptism in 1610, and the complex implications of his logically deduced theistic belief for both Confucianism and Christianity.