We examined the pattern and direction of behaviors that reflect infants' underlying mastery motivation. The sequences of mastery behavior were analyzed in a sample of 67 infants when they were 6 and 12 months old. We computed (a) the frequencies of each of six categories of mastery behavior, transitional probabilities, and z scores for each possible behavior change between the categories and (b) the transitions from a mastery behavior to an instance of positive affect. The analyses revealed significant age changes in the frequency of each category; however, the significant transitional probabilities among the six categories displayed a similar organization at both ages. The transitions from a mastery behavior to an instance of positive affect suggest that it is persistent, goal-directed behaviors that contribute to an infant's feeling of efficacy.