Preterm infants have been found to be at-risk for both cognitive and emotional developmental deviations and for clinical problems in later childhood. Yet, systematic, longitudinal developmental examination of the differing characteristics of the affective expressions of preterm infants, as compared to normals, is lacking in the literature. The proposed study focuses on this particular line of development during the second year of life in two groups of infants: preterm infants without medical complications and full-term infants. The aim is to apply refined techniques of categorizing and measuring several aspects of early affective expressions, and the regulation thereof, in order to characterize the possible differences in the patterns of affective development between these two groups. The findings will contribute toward better identification of risks for healthy emotional development. It will also lead to specific hypotheses for future investigations. The behavior of 8 preterm and 8 fullterm infants in the presence of the mother and of the examiner/stranger will be videotaped at 3 months intervals between 12 and 24 months of age, using a Clinical Assessment Procedure (CAP). The CAP entails eight episodes of mother-stranger-infant interactions that is based on similar procedures developed by Ainsworth et al. (1978), Broussard (1979), and Gaensbauer et al. (1979). Blind raters will assess the following affects: pleasure, distress, anger, interest in mother, interest in stranger, interest in toys and room. The coding scheme is a modified version of that developed by Gaensbauer et al. (1979). Both cross-sectional and longitudinal approaches will be employed in the analysis of the data.