The -purpose of the present study was to investigate developmental changes of criteria of organization in memory retrieval. Subjects were 38 5-year olds, 38 6-year olds, and 20 9-year olds. Three criteria of organization were chosen as strategies for retrieval; perceptual (color), complementary (function, spatial and temporal contiguity), and conceptual. These were tested through the use of sets of picture cards, divided according to a standard and the three criteria. Main results were (1) the color criterion was consistently lowest in all children; (21 the complementary criterion was utilized most in 6-year olds; (3) 9-year olds utilized both the conceptual and the complementary criterion; and (4) the use of conceptual criterion increased with age. Results are discussed in terms of developmental changes in the utilization of criteria of organization at retrieval.