I. Problem. This study is one of the action-research projects of the development of student baseball team activities in Kyushu University. The purpote of this study is to analyse their interpersonal relations and to make deveop the human relations in team activities. II. Subjects. Subjects are 16 members of baseball team in Kyushu University. They need not always to have special ability for baseball. The team is composed of those who want to play baseball, even if their ability isnot specially fitted to it. III. Ist ent; Study of the relationship between the individual motor fitness and ability of sociol adjustment. (1) Motor fitness and ability of baseball. The general motor fitness test was given to 14 members. Tie test consists of six factors, namely, strength, power, abillty, flexibility, endurance and balance. The rank order from the first to the fourteenth was made by the results of this test. At the some time, the batting rank order was made by the batting achievement of last year. The rank correlation between the order of motor ability and batting order was 0.174 except one who was the 12th in the motor fitness and the 3rd in the batting order-a very hard worker and a typical overachiever. By the results of questionair which was conducted to the members partiepating in the first camp training this year, it was found: (a) During five days of the camp training 63% of all members felt the existenc of the cohesiveness of the group as a whole. (b) Some 80% of all members began to have friendship each other. (c) Some 70% became awars of the progress of their achievement. (d) 54% suffered from conflicts between the academic studies and team activities. (2) Interview survey The aim of this study was to inquire more personally about the same items as that of the above mentioned question. Its results were as follows; (a) Tho drgree of the cohesiveness of the team as a whole was high. (b) There were many members who felt that the schedule of the 2nd camp training was too tight. (c) It was found that each member called each other with nick-name. (d) They had much interest in the discussion sessions, held twice during the camp training. (e) Only one member displayed sometimes an agressive behavior. He was sometimes late at the open hour of the camp training. In accordance with the results of the Scciogram as will be described later, he was an isolate. (3) Sociometric survey. The sociometric survey was carried out on the last day of the 1st and the 2nb camp training. The formulae of question were as follows: Among your team members, (1) Whom would you want to go to a tea shop with? (2) Whom would you want to take lodgings with? (3) Whom do you like best? (4) Whom would you like as your partner of your experiment? Its results were as follws: (a) The frequency of the choice increased 0.75 for each person in the 2nd camp training, in comparison with the 1st camp training. The results may be interpretated in this way that the camp training had a good influence on the development of the human relations in team activities. (b) Those who had the feeling of inferiority enjoyed a very little popularity. (5) The 3rd Experiment. A study of res lying the conflicts between the academic studies and team activities. (1) By the results of the pre-test, it was found that all members felt, more or less, conflicts, between academic studies and team activities. (2) Introducing the persuasion as a means of resolving the conflicts. The content of persuasion was as follows; At the 1st step, the President of baseball club announced at the presence of all members of baseball team to the effect that: Even if there are some negative aspects in baseball team activities at present time, the experience of club activities will be very much helpful in the light of the whole life experiences,