The developmental change of conformity was investigated in an Asch-type situation with 345 children from the elementary school, the junior and the senior high schools. The Asch-type stimuli were used, and the difference of response by age was observed in the peer-, teacher-, mother-pressure conditions. Main results were: (a) In the Peer condition the quadratic relation was found between age and conformity, with the highest conformity between the 4th and the 6th grades in the elementary school, (b) in the Teacher condition the cubic relation was found, (c) in the Mother condition the linearly decreasing relation with age was found, (d) the relationship between perceptual patterns and conformity was also investigated.