The purpose of this study is to identify; (a) the relationship of cognitive style to adjustment mechanism, (b) the relationship of locus of control to adjustment mechanism, and (c) the relationship of cognitive style and locus of control to adjustment mechanism. Subjects were 285 college students(146 males and 139 females) of Kyungpook National University. They were administered Group Embedded Figures test (GEFT), the revised Rotter’s Internal-External Locus of Control Test (I-E), and Diagnostic Adjustment Mechanism Inventory (DAMI). DAMI was designed to measure the relative intensity of three major groups of adjustment mechanism such as defense, aggression, and escape mechanism. Correlational approach was used to identify the relationship of cognitive style to adjustment mechanism, the relationship of locus of control to adjustment mechanism, and the relationship of two variables of cognitive style and locus of control to adjustment mechanism. The results of this study were as follows; 1. The variable of locus of control is positively related with defense mechanism for both male and female. It can predict reliably the degree of defense mechanism used by the subjects. 2. The variable of locus of control can reliably predict degree of aggressive mechanism used by female students. 3. Combination of locus of control and cognitive style has no more predicting degree of defense mechanism adopted by the subjects. 4. The predictive power of combination of locus of control and cognitive style is not significantly higher than that of the locus of control variable alone in predicting degree of aggressive mechanism used by the subjects for both sexes.