The two document factors, the length of an article and the number of references, play different role on different subjects. In addition, no scholar tests the impaction of the length of title and the number of keywords on the citation of an article. With 455 articles from 6 fields, this paper tests four document factors impacting on the citation of an article, which are the length of an article, the number of references, the length of title, the number of keywords. The results are followings : First, the number of keywords influences the possib...