The purpose of this study is to analyze effects of teacher intervention, such as conversation, redirection and participation in play activity, and social interaction in Kindergarten children. To these ends, five hypothesis were set up in this study. l. Between the experimental group with a traind teacher in intervention methods and the control group without a trained teacher, there will difference in duration of group play activity of high social complexity level. 2. Between the two groups mentioned above, there will be duration differences in dramatic play of high cognitive level. 3. In the two groups mentioned above, there will be duration differences in group dramatic play of high social and cognitive comlexity level. 4. Between the two groups mentioned above, there will be duration differences in reciprocal social play. 5. Beween the two groups mentioned above, there will be duration differences in non-play activity. The subjects of the study were two teachers and twelve children:six boys and six girls. These children were classified into an experimental and a control group. The experimental study was carried out of 40 minutes daily, Monday through Friday for 7 weeks. The experimental procedures were in the order of pre-experiment, pre-test, teacher training for intervention, experimental treatment, and post-test. Scences of each test were recoreded with a video camera, which was reviewed by trained observers measuring duration of children`s play activities. Instruments developed by the reseacher were used for measures of play activity complexity and of social interaction. The average and the standard deviation of the collected data were computered by SPSS Computer Program and analyzed by ANCOVA. The conclusion of this study, thus, is that use of teacher`s suitable intervention influenced comlexity level of play and level of social interation in children`s dramatic play.