Background : Body image dissatisfaction (BID) tendency is a diagnostic item for an eating disorder (ED) and body checking (BC) is a behavioral feature of ED. A relationship between BID and BC has been hypothesized. It has been reported that mirror exposure (ME) is an effective intervention method for improving BID and BC. In ME, the client looks at the whole body in a mirror for about 1〜2 minutes, doing as little evaluation as possible. However, the precise relationship between BID and BC has not been shown and the cognitive processing style during ME has not been clarified. The purpose of this research was to clarify the relationship between BID and BC by using questionnaire survey, and to experimentally examine the subjective way of viewing the whole body in a mirror based on the differences in BID tendency. Method : Participants were female college students (n=382 : mean age 20.0 years, SD=1.69) attending the Waseda University, in Tokyo, Japan. Participants responded to the following questionnaires : (1) Eating Attitude Test-26 Japanese version (EAT-26), (2) Body Image Dissatisfaction measure (BID measure), and (3) Body Checking Cognitions Scale Japanese version (BCCS). Seven participants (Mean age 21.7 years, SD=5.02) who consented to the participation in an experiment were divided into two groups based on their BID measure ; namely those with an average score of 59.1, +0.5 SD were included in the high BID group (H group) and the others in the normal BID group (N group). In the experiment, participants were asked to freely look at their whole body in a mirror for 5 minutes. After that, the participants responded to a questionnaire inquiring about their feelings when looking at the mirror, as well as their usual feelings about their body. Results : In EAT-26, BID measure, and BCCS, a moderate significant positive correlation was shown, respectively (r=0.412〜0.538, p<0.01). Moreover, a weak but significant positive correlation was shown in the partial correlation of BID measure and BCCS, after controlling EAT-26 score (r=0.253, p<0.01). When the numbers of body parts that H and N groups intentionally looked at were compared using a Wilcoxon rank sum correlation test, H group inclined to look at larger numbers of body parts than N group did (p=0.0692). Similarly, H group showed a significantly larger difference represented by the absolute value between the degree of usual negative feelings about the most disliked body part and negative feelings when looking at it in a mirror than N group did (p=0.0498). Considerations : The study indicated a relationship between BID and BC regardless of ED tendency. Moreover, people with strong BID experienced different feelings when they usually think of their body and when they look at their body in a mirror. It is suggested that this could be because they avoid looking at the parts of their body resulting in negative feelings in their daily life when looking in a mirror. Conclusion This study indicated a relationship between ED and BID and BC, and a possibility that people with strong BID avoid looking at the parts of their body. Therefore, it is expected that presenting ME to people with strong BID will stop avoiding their body image and improve body image overestimation (/underestimation).