Abstract: The research performance of doctoral students is recognized as the overall reflection of research outcome, the level of research performance would directly evaluate the quality of doctoral education. Therefore, the performance management plays a key role in the education quality. In existed studies, the impact factors selection for doctoral research performance is not systematic, and the impact of subjects on the doctoral research performance is never considered before. The SCI-journals rate which doctoral students publish papers in is selected as a dependent variable; quality of students, mentor influence, and learning performance are selected as impact factors of research performance, and subjects are selected as the moderator(comparison between physics and chemistry). The samples are collected from graduated doctoral students of University of Science and Technology of China (USTC) in the years of 2002 and 2003, which are 139 students with the major in physics and 167 students in chemistry. The results of Logistic regression analysis indicate that subject moderate the relationship among doctoral students' research performance, quality of students, mentor's academic status, and number of students.

Key words: doctoral student, research performance, subject difference