The current research aims at exploring: 1. Motivation of mastery in university students. 2. Statistically significant differences in mastery motivation according to gender (male, female) and specialization (scientific, human). The researcher has adopted the mastery motivation scale, which consists of (24) items. It is exposed on a group of experts to judge the validity of its items. The psychometric properties of it are ascertained by administering it to the research sample that consists of (400) male and female students from the University of Wasit, they are chosen by using the stratified random method. The researcher has ascertained the reliability of the scale in two ways: by using re-test where the reliability coefficient is (0.84), and by using Alphcronbach equation, which is (0.82).