Purpose: The purpose of this study was to investigate the effects of a small group collaboration learning program through MBTI on nursing professional self-concept and career maturity of nursing college students. Method: A randomized control pre-post test experimental research design was used. There were 30 sophomore nursing students in the experimental group and 30 in the control group randomly assigned and randomly selected from the nursing program of T University in Daegu, Korea. The program through MBTI was developed by Kwon (2002) using a program by Shim and Kim (1997) as treatment. The experimental group received the program through MBTI for 30 hours (2 times a week for 15 weeks) while the control group received no treatment except a series of tests. Measures were the MBTI test, nursing professional self-concept scale, and career maturity scale. The data were analyzed with SPSS Win 17.0 program, chi-square test, and t-test. Result: The experimental group which received the program through MBTI had a higher score of nursing professional self-concept and career maturity change than the control group. Conclusion: A small group collaboration learning program through MBTI was effective in increasing nursing professional self-concept and career maturity of nursing college students.