The purpose of this study was to investigate the relationship between infants' attachment to mother and mothers' responsiveness to behaviors of her infant. Twenty-four male and 24 female 12-month-old infants and their mothers were videotaped at a laboratory in the Ainsworth-Wittig strange situation and in a series of subsequent situations designed to provide opportunities for distinguishing between levels of maternal responsiveness. In the last of these, a questionnaire situation designed to measure maternal responsiveness, each mother-infant dyad was filmed for 3 minutes in the same room where the mother was asked to fill out the questionnaire and the infant was allowed to explore the room. The room did not contain toys and as such the children could not occupy themselves with toys. Each mother was also told to feel free to interact with her child in any way she liked during this situation. Before leaving the laboratory mothers were asked to complete a toddler temperament scale. Strange situation behavior was scored for proximity and contact seeking, contact maintaining, resistance, and avoidance behavior in accordance with guidelines provided by Ainsworth. Measures of maternal responsiveness to infant behavior in the questionnaire situation were based upon maternal vocalization and touch following infant attentional demands. Results are discussed. It is concluded that the measures designed to assess maternal responsiveness developed in this study, while needing further refinement, appear to be a promising tool for the study of maternal behaviors related to attachment. (Author/RH)