Abstract:Japanese literature derived from Man'yoshu, the spiritual homeland of Japanese people. Man'yoshu provides a rich source for the Japanese literature, and has been known as Japan's The Book of Songs. The poems in Man'yoshu, in a plain and natural style, vividly depict Japanese society at ancient times when the feudal system enjoyed a period of growth. As a masterpiece of the classical literature, Man'yoshu has a great impact on the development of the literary works in the later ages. Based on the research of Japanese Confucianism, the paper tries to give an interpretation of what is the connotation of "Sincerity (MAKOTO)"which is an important esthetic philosophy contained in Man'yoshu.