Of the predictor variables in this study, behavioral skills (self efficacy) for self-management had the strongest direct effect on self-management behavior. At the same time, this variable was also a mediating factor for the effect of social motivation on self management behavior. This finding confirms the result of previous studies [35-39], which reported that self efficacy is the most important core factor influencing the performance of diabetes self management behavior. In other words, when individuals engage in self-management behavior, their personal determination and confidence in controlling and performing the behaviors successfully are the core factors leading to behavior change. Moreover, the value of the direct effect of behavioral skills on self-management behavior (b = .76, p = .003) was found to be relatively high compared to that of Choi's study which had patients over 65 years of age (b = .62, p = .006) and that of Osborn et al.'s study which had patients in their 50s and 60s (b = .45, p < .001). This suggests that the effect of self efficacy on self-management behavior is stronger for young people with type 2 diabetes than it is for older patients.