This study compares academic library use of undergraduate students in the united states and undergraduate students in Taiwan. Frequency of library use was treated as a dependent variable to determine the best predictors from 16 independent variables via a questionnaire administered to junior students in the University of Wisconsin-Madison in the U. S. and the National Taiwan University in Taiwan. The items composing the dependent variables of library use were factor analyzed to determine the underlying structure of the purposes of library use and the frequency of library use. For both samples, two factors explained well over 50 per cent of the variance in the items: NONCOLLECTION USE and COLLECTION USE. The factor scores for these factors were used as dependent variables with 16 predictors, and backward method of multiple regression was applied to extract the best predictors for each sample. The results indicated that the situational variables such as the requirement of term papers, assigned reading beyond textbooks, instructor's encouragement to use the library, and the need for a quiet place to study were the most important variables in the American sample, interacting with psychological traits, library-relationship variables, and demographic variables in their relationship to undergraduate library use. In the Chinese sample, demographic variables such as mother's educational level and psychological variables such as dogmatism, and antiintellectualism were more important than situational variables in their relationship to undergraduate library use.