Motivation is identified as one of the most powerful influences on learning. However, in interpreter training, motivation has not been given due attention, especially in China when most interpreter training programs are newly-established and are still focusing on hard-skill acquisition. This paper reviews the existing researches on interpreting learner motivation and reports the initial results of a questionnaire survey conducted in 2012 among the students of the Graduate School of Translation and Interpretation, Beijing Foreign Studies University. Factor analysis on the survey data identifies 8 major interpreting learning motives of the students surveyed and shows that the dominant learning motivation at the graduate level is of instrumental and extrinsic nature. Comparative analysis of the two student groups also supports the SDT continuum of learning motivation.