The process by which preschoolers generate cohesive oral text was investigated in two fields of discourse: social dramatic and constructive play. Four preschoolers, 2 boys and 2 girls, ranging in age from 51 to 60 months were observed and videotaped in their regular preschool classroom on 2 successive days during free play periods. Each child was observed for 2 fifteen-minute sessions: one social dramatic play episode and one constructive play episode. All social dramatic play took place in the center's housekeeping corner. Constructive play took place in the block corner. Utterances were transcribed verbatum, noting speakers' turns and contextual variables. Utterances were coded according to Halliday and Hasan's (1976) model of cohesion. It was found that the building of cohesive text in both play contexts was dependent upon the topic introductory utterance, the utterance which marks the beginning of a new play topic and, consequently, new text. In both contexts the predominant strategy used by children to introduce a topic was to repeat introductory utterances and key lexical elements related to the introduction. Clarification strategies were observed in social dramatic play, but not in constructive play. Social dramatic play seemed to rely upon verbally encoded play themes for sustenance. Constructive play themes were based on children jointly manipulating objects. (Author/SS)