1）The Buddhism philology. My dissertation for doctor is Study on The Transmission of the Lamp.This is the important Zen text, containing the biographies, dialogues of 1700 Zen masters. My post-doctorate topic is the Chinese catalogs. At present, I attempt to establish the system of the Chinese Buddhism philology. 2)Buddhism literature, especially, the relationship of the Chinese classic literature and the Buddhism . 3)Buddhism history. I deal with questions of Buddhism history mainly using the excavated literature, such as the documents of Heshui city, and the pagoda inscription.