This study was carried out to assess the perception of decisional balance of Korean subjects about 4 health behaviors and to identify the influencing factor of decisional balance for exercise acquisition, smoking cessation, mammography screening and Kegel's exercise acquisition. All are representative health behaviors nurses can intervene in Korea based on the Transtheoretical model. Convenient samples of 2,484 subjects (191; exercise, 169; smoking cessation, 1903; mammography screening and 221; Kegel's exercise) were selected from cities and counties over 9 provinces throughout Korea, and the data was collected from January 1, 1999 to February 29, 2000. The research instrument were the Decisional Balance Measure for Exercise (Marcus & Owen., 1992), Smoking Cessation (Velicer et al., 1985), Mammography Screening (Rakowski et al.,1992) and Kegel Exercise (Lim, 1999) and Stage of Change Measure for Exercise (Marcus et al, 1992), Smoking Cessation (DiClemente et al., 1991), Mammography Screening (Rakowski et al.,1992) and Kegel's Exercise (Lim, 1999). The data was analyzed by the SAS Program. The results are as follows; 1. According to the stage of change measure, 2,484 subjects were distributed in each stage of change for four health behaviors: 1,233 subjects (49.8%), 745 subjects (30.2%), 113 subjects (4.7%), 156 subjects (6.5%), and 216 (8.7%) belonged to the pre- contemplation stage, contemplation stage, preparation stage, action stage and maintenance stage. They were all series of stages of change in their efforts to do health behavior. 2. Factor analysis identified 3 factors (1 of Pros, 2 of Cons) for the exercise, 4 factors for smoking cessation (2 of Pros, 2 of Cons), 2 factors (1 of Pros, 1 of Cons) for the mammogram screening and 2 factors (1 of Pros, 1 of Cons) for Kegel's exercise of decisional balance. 3. The analysis of variance and multiple comparison analysis showed that for all 4 samples, the Cons of changing the problem behaviors outweighed the Pros for subjects who were in the pre- contemplation stage, The opposite was true for subjects in action and maintenance stage. 4. Through the discriminant analysis, it was found that one factor of Pros for exercise, one factor of Cons for smoking cessation, 1 factor of Cons for mammogram screening and one factor of Cons for Kegel's exercise were the more influencing factors, than others in discriminating the stages of change. Results are consistent with the applications of the Transtheoretical model, which have been used to understand how people change health behaviors. This results provide some evidence that subject's report of his/her health behavior corresponds to beliefs about usefulness of related health behaviors. The results of this study have implications for patients' health education and health intervention strategies. The findings of this study give useful information for nursing educators for 4 health behaviors, especially the factors relating to decision making in the different stages of change.