It is well-known that Buddhist monastic life contradicts Confucianist secular life. In order to solve this contradiction, some scholars before Tang Dynasty explained from the Buddhist perspective; some compromised with Confucianists; while others claimed that people could save their parents after they became a monk and accomplished Sādhana. None of these theories solve that problem completely. In Tang Dynasty, Confucianism and Buddhism further integrated with each other. In this background, Buddhist scholars wrote three commentaries on Yulanpen Sutra (Yulanpen Sutra Zanshu kept in Shanghai Library, Yulanpen Sutra Zanshu kept in France and A Commentary on Yulanpen Sutra), which contains a more systematic and reasonable solution to the conflict. By stressing the emotion of willingness to repay the parents, praising "filial piety" more and giving a new explanation to "requiting parents", they concluded that the aim of being a monk and pursuing the Dao is to help their parents to achieve the Dao, they solved the conflict between Buddhism and Confucianism on "filial piety".