Purpose: The purpose of this study was to investigate the effects of using a social skills training program to address problem behaviors, social skill, and peer relationship in children using a community child center in a vulnerable area. Methods: The research design was a non-equivalent control group pretest-posttest quasi-experimental study. Participants in the experimental group were 25 children, recruited from a community child center in G-city. Participants in the control group were 25 children, recruited from a community child center in S-city. Data were collected from September, 2014 to January, 2015. Outcomes were measured using the Child Problem-Behavior Screening Questionnaire (CPSQ), Social Skill Rating System (SSRS), and Peer Relational Skills Scale (PRSS). The experimental group participated in the social skills training weekly for 10 weeks. Statistical analysis was performed using the SPSS 18.0 program. Results: Significant differences were found in problem behaviors, social skills, and peer relationship scores between the two groups. Conclusion: This social skills training program was found to be effective in reducing problem behaviors and improving the social skill and peer relationship of these children, and is recommended for use in community health services as an effective nursing intervention for children in vulnerable areas.