The purpose of this study was to examine the mediating effects of difficulties in emotional regulation of middle-aged men and women in Korea through maladaptive self-focused attention and hypochondriasis. The subjects of the present study were 319 middle-aged men and women living in Seoul, Incheon, Yangsan and Cheongju from July, 2016 to the end of September. K-DERS, HMS of MMPI-2, and SDSAS were used for the measurement. The SPSS 22.0 was used for Pearson correlation analysis for the mean and standard deviation for the characteristics of the subjects and the relationship between the variables. In addition, SPSS Macro was used to confirm the mediating effect of the difficulties in emotional regulation in relation to maladaptive self-focused attention and hypochondriasis. The SPSS macro bootstrapping was also used to verify the significance of the total mediator effect and the indirect effect The Cronbach s a of the scales was .920 for difficulties emotional regulation and .948 for maladaptive self-focused attention. All showed high internal consistency. Since the hypochondriasis was converted to the T score of MMPI-2, the reliability coefficient was not calculated. As a result of the analysis of the mediating effect, the difficulties of the impulsive control (β=.070, p<.05, CI:[012~.134]) and the emotional clarity (β=.086, p<.05, CI: [.008~.166]) was found to be significant. The significance of this study was to examine the mediating effects of maladaptive self-focused attention, and hypochondriasis on difficulties in emotional regulation, and to understand the difficulties in emotional regulation, maladaptive self-focused attention, and hypochondriasis. The results could reduce the psychological burden on middle-aged men and women in Korea and contribute to clinical research.