This research examines the relationship between university student’s smart phone addiction and college
adjustment, and explore whether cognitive flexbility gives mediating effect to smart phone addiction and
college adjustment. The study study subjects of this work were 300 students who were in the 1st to 4th
year of the S University located at W. This work conducted a questionnaire survey with the study subjects
on the basis of the following study tools : Smart phone addiction Scale who adapted Hea-jin Park(2013);
College Adjustment Scale(SACQ: Student Adaptation to College Questionnaire) developed by Baker et al.
(1989) and adapted by Youn-jung Lee (1999); and Scale for Individual Flexbility developed by Sook-ji Hong
(2006). The results of this work are summarized as follows: First, the correlation between main variables was
analyzed. As a result, it was found that smart phone addiction had a negative correlation with college
adjustment, and cognitive flexbility had a negative correlation with smart phone addiction, and cognitive
flexbility had a positive correlation with college adjustmen. Secondly, to examine the mediating effect of
cognitive flexbility in the relationship between smart phone addiction and college adjustment, this work used
Sobel test. As a result, it was found that cognitive flexbility gave partial mediating effect to the relationship
between smart phone addiction and college adjustment. This means that college adjustment was affected not
only by smart phone addiction, but also partially by cognitive flexbility. As smart phone addiction has
emerged as a social issue, more low activity reports about personal relations, academic and work without
communication. The smart phone addiction cause the issue of adjustment, and even will worsens it. Therefore,
to efficiently handle clients with college adjustment, it is necessary to take into considerration smart phone
addiction and the cognitive flexbility. This work also suggested discussions about the study results and its
limitations.