In the competitive sports, it is essential that the players should have mental strength in bringing their skill and talents fully into play. It is important not only for the professional or senior athletes but also the junior athletes to have mental strength. Tokunaga developed the Diagnostic Inventory of Psychological Competitive Ability for Athletes, as a method for diagnosing athletes' psychological traits. The purpose of this study was to investigate the psychological competitive ability for junior youth soccer players using Diagnostic Inventory of Psychological Competitive Ability for Athletes (DIPCA. 2). The subjects were made on 177 junior youth soccer players from Keio Futsubu soccer team (K:n=55), Gyosei middle school soccer team (G:n=55), and Kawasaki Flontale soccer club (F:n=67). Average of total scores in all subjects was 166.6 ± 21.96, between the teams, F scored highest in the three teams, the second was G and K was lowest (F: 179.2 ± 21.57, G: 164.8 ± 20.46, K: 156.2 ± 19.98). In comparison of different team, F was higher in volition for competition, confidence, and strategic ability than K and G. On the other hand, there were no significant differences for mental stability and concentration. These results suggested that the psychological competitive ability for junior youth soccer players was influenced by the member structure and/or the training environment (coaching staffs, training programs etc.) except for mental stability and concentration.