The purpose of this study was to examine the effects of assertiveness training on the enhancement of assertive behavior of nursing students. Subjects for this study were ten nursing students. Subjects were assessed before and after the training on assertive scale. They were trained by assertive training program for five weeks. The training program was consisted of instruction, role playing or behavior rehearsal, feedback, modeling, and home work assignments. The contents of group training were combined of the comparison of passive, assertive, and aggressive behaviors, giving and taking compliment, requesting and rejecting, rational-emotive therapy. The effects of assertive training were assessed using Korean version of Rathus Assertiveness Scale. Analysis of the data was done by use of paired t-test to examine the pre-post difference of assertiveness training. The results showed that assertiveness training. The results showed that assertiveness training was effective on the enhancement of assertive behavior of nursing students.