The paper deals with research results of prevenient part of joint activity in youth groups. The objective of research was to study that phenomenon as a group process of preparation for joint activity which defines its productivity. Methods of observation and device «Arch» were applied to study three youth small groups in summer camp located in Krasnodar region. It was empirically established that youth groups subject to the level of orderliness are different in performing both prevenient and executive parts of joint activity. The research confirmed the data received in the groups working in extreme conditions of joint activity and revealed the leading role of group leadership in the prevenient part of joint activity.