The ability to effectively, positively, and productively cope with social problems is considered one of the most important developmental tasks for children's emotional and psychosocial adjustment. However there is a paucity of empirical research on children's competent problem solving (CPS) in early school years. CPS is a process of finding solutions to specific problems, including the use of cognitive and emotional competencies. Early family and peer experiences have always been focuses of researchers in explaining individual difference in children's social cognition development. The present study examined the early positive parenting (maternal warmth, parental involvement, proactive guidance) and peer experience (peer acceptance) on the developmental trajectories of the last three components of CPS (competent response generation, evaluation, and efficacy) from kindergarten to third grade. Data were collected from the Child Development Project, a prospective longitudinal study of child and adolescent development from a community sample of children and their families (N=585). Three positive parenting practices (i.e. warmth, involvement, and guidance) were assessed in kindergarten, and three components of CPS (competent response generation, evaluation, and efficacy) were assessed the summer prior to kindergarten and in grades 1, 2, and 3. Positive peer experience was assessed via sociometric ratings and teacher-reported peer relationships at kindergarten. Analyses revealed that three components of CPS are relatively independent, and competent response generation may be the most salience factor of CPS. Result also suggested that children's competent response generation, evaluation, and efficacy increases from kindergarten to 3rd grade. Maternal warmth and parental involvement benefits children's competent response generation and evaluation. However, children with higher proactive guidance had a slower growth rate, whereas children with lower proactive guidance had a faster growth rate of competent response evaluation. Peer acceptance is especially helpful for children's development of competent response generation. Additionally, findings support an additive effects of maternal warmth and peer acceptance on children's competent response generation. Results of the present study underscore the importance of examine the competent processing in a developmental perspective, and suggest that the different developmental patterns may depend on parenting and peers experiences. Findings and implications for earlier positive parenting, peer acceptance, and children's CPS are discussed. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]