The purpose of this study is to investigate the relationship between academic and career stress, self-efficacy, and adjustment to college. To accomplish this purpose, this study set up the specific questions as follows: a) To examine the relations of academic stress, career stress, adjustment, and self-efficacy; b) to examine mediation effects of self-efficacy between stresses and adjustment. Data were collected from 230 students(112 male, 118 female) sampled from universities in Seoul, Gyeonggi, and Chungbuk province, Korea. The survey instruments used for this study were Academic stress scale(Cronbach's α=.88), Career stress scale(Cronbach's α=.87), Self efficacy scale(Cronbach's α=.87), and Adjustment to college scale(Cronbach's α=.86). They were all developed or validated by Korean professionals according to Korean sociocultural environment. The statistical method employed for the data analyses were correlations, t-test, regression analysis, SEM by using SPSS 12.0 and AMOS 4.0 programs. The results of this study were as follows. First, in the adjustment to college according to academic stress, career stress, and self-efficacy, there were statistically significant differences between upper class and lower class. It was found that average of the lower class of academic and career stress, and upper class of self-efficacy were high. Second, the mediation analyses revealed that the relations between academic and career stress and adjustment to college were partially mediated by self-efficacy. In conclusion, this study confirmed that adjustment to college was affected by academic and career stress and self-efficacy. Also, self-efficacy partially mediates between stresses and adjustment to college. Therefore, to maximize of adjustment to college, it is needed to promote self-efficacy as a motivational variable. The implication and limitations based on these results were discussed with some suggestions for the future researches.