The intermingling of the theory of mind and nature in Daoism and Buddhism is a big problem in the history of Chinese thought. This essay would like to proceed from the notions of Dao, Zi Ran, no exerted effort and everything gets done, silent observation and capturing the meaning and forgetting the words in philosophical Daoism and examine their influence on Buddhism. It would like to emphasize that philosophical Daoism, especially Zen, contributed largely to the basis of Buddhism's ontology, methodology and epistemology. From the perspective of religious Buddhism, I would like to take a look at transmigration and retribution, the dharmas are all empty, the dharmas are produced in the mind, and the enlightened mind sees the nature(明心見性), and their influence on religious Daoism. This in emphasizing that religious Buddhism had a great influence on religious Daoism in the realm of life ideals. In cultivating the mind and nature of man, Chinese Buddhism and Daoism drew from and complemented each other, creating a unique philosophical synthesis.