One form of educational provision that has been widely noted to have a positive and significant impact for T2DM patient is Diabetes Self-Management Education and Support (DSMES). One of methods of administering DSMES that considered effective and provides convenience to patients is by using internet technology such as applications. The purpose of this study was to determine the effect of application- based DSMES on self-care behavior in Type 2 Diabetes Mellitus patients. This study was a quasy experiment with pretest-posttest with control group design. The research sample was 50 people choosen by simple random sampling technique and divided into 2 groups. The statistical analysis used is the Wilcoxon and Mann- Whitney test. The results showed a significant increase in self-care behavior in the intervention group (p value .000). There were 5 categories that had significant changes, there were Diet (p value .000), Blood Sugar Test (p value .001), foot care (p value .000) , treatment (p value .006). The conclusion of this study is that application-based DSMES can increase the ability of self-care behavior possessed by Type 2 Diabetes Mellitus patient.