Developing effective Psychological Skill Training program for Players is a strategy for improving Team cohesion, Aggression and motivation. The purpose of this study was to investigate the effect of PST on team cohesion,aggression and Motivation variables. The study employed Experimental research design.60 male football project players of Addis-tesfaand key-meskel of Mekaneselam with the age of (EG=15.93±4.803, CG = 14.8±.94) had divided randomly into 2 equal groups. Both the exercise group (EG, n = 30) and control group (CG, n = 30) participated in the typical training program 2 days of 1:30hours per week in schools, but only EG participated in additional 6 week PST interventions which comprised as goal setting, self-talk, pep talk, imagery, progressive relaxation techniques, team building strategies and relaxation response techniques were given through 3 phases which comprises educational, acquisitions and practical phases by psychologist. Both groups had taken pre and post-testing and all the subjects participated to response standard questionnaires: team cohesion was measured using group environment questioners, aggression were measured using smith aggression questioners and motivationwere measured using sport motivation scale test. The data collected from the study subject was analyzed using SPSS version 20 software by paired t-test with level of significant 0.05. The results showed PST significantly improved the stated variables team cohesion, aggression and motivations in EG at (p<0.05). Furthermore, no more significant differences were found in all of the variables in CG (p>0.05). Based on this finding, it can be concluded that PST has positive effect on improvement ofpsychological skill variables.