Abstract: The total amount of Tang and Five Dynasties′ literature studies in China and abroad in 20th century reaches 34,818 items. The yearly achievement yield varied significantly with high yield in slump periods and low yield in peak periods. On the whole, the centennial research can be divided into four phases: the initial stage of taking first steps (1901—1919), the second stage of edging forward (1920—1953), the third stage of marching forward (1954—1981), and the fourth stage of rapid taking off (1982—2000). The achievement yield of the Tang Dynasty literature studies home and abroad in the 20th century has two major features. One is the unbalance of the achievement increase among different periods, taking the trend of early low and later high. In the first three periods, although the achievement yield increased gradually, the overall amount was still low, but in the last period of 1980s and 1990s, the yield took off dramatically. Secondly, the research hot issues take on the features of continuity and homoplasy on the one hand and differentiation on the other hand. From the time angle, since the studies of individual writers became popular in the 1920s and 1930s, the hot topics had been quite concentrated, focusing on Du Fu, Li Bai, Bai Juyi, Han Yu, Liu Zongyuan, Wangwei, Li He and Li Shangyin. From the angle of space, the research focus home and abroad is basically on some famous poets such as Du Fu, Li Bai, Bai Juyi, Han Yu, Liu Zongyuan, Wangwei, Li He, Li Shangyin, Liu Yuxi and Du Mu. But there were still differences: domestic scholars favored poet studies, while overseas scholars focused on both poets and novelists. 

Key words: Tang Dynasty literary studies, achievements yield, quantitative analysis, measuring academic history, Price′s Law