The purpose of the research is the development of the Preschool Self-Regulation Program and the examination of the effect of the program on children's self-regulation skills, problem behaviors and social skills. The research designed in the embedded design; the quantitative dimension is quasi-experimental design with pre-test post-test control group, and the qualitative dimension is basic qualitative research. Working group consists of 52 children, 26 of whom are in the experimental group, 26 of which are in the control group, and two teachers in the experimental group. Quantitative data were analyzed by MANOVA and t-test for dependent samples, and qualitative data were analyzed by deduction method. In the study, a program consisting of 21 sessions, 7 weeks and 3 days a week, was applied in the experimental group. In the results of the research; while there was a significant difference in the pre-test post-test scores of the experimental and control groups in self-regulation skills and social skills, there was a significant difference in problem behaviors only in the experimental group. There was a significant difference in favor of the experimental group in the post-test scores of self-regulation skills, social skills and problem behaviors. When the qualitative findings of the study were examined, it was concluded that while there was an increase in self-regulation and social skills, there was a decrease in problem behaviors.