The present study aimed mainly at demonstrating the effect of two different sensory-motor cues on trausformation of spatial representation in children. A simplified version of Piaget's “-mountainsexperiment” was undertaken here through experiments I and II. Experiment I The subjects were 30 boys and 30 girls. They were ranged in age from 4 ; 8 to 6 ; 9. In place of three mountains three objects, i. e., a cube, a bowling pin, and a cylinder, were used. The experiment ran as follows ; the three experimental situations were put into practice. (A) To predict the object's locations of a covered landscape after having turned the turn-table for 180 degrees on which the objects were arranged. (B) To predict the object's locations of a covered landscape after a child removed around turntable for 180 degrees. (C) To identify object's locations (perspectives) from the opposite position, in which a doll stood.(The Piaget-type task) Generally, moving around himself was more effective on the transformation of image than turning the stimulus frame, and (C) was most difficultfor children. There were no significant differencesbetween younger and older children. Experiment II The subjects were 23 boys and 29 girls at the age of 7. In the pre-test, the same materials as Experiment I were used according to the Piaget-type procedure. Ss were divided into four homogeneous groups according to the pre-test score. Each group had different experience at the next interim test. Group I: After the subjects turned the table for 90 or 180 degrees and then observed each objects' location during 15 seconds, they turned the table back to the original position and then reconstructed what they had seen. Group II: After the subjects removed around the turn-table for 90 or 180 degrees and then observed each objects' locations during 15 seconds, they went back to their original place and then reconstructed what they had seen. Group III: Having verbalized right-left and before-behind relations from various positions, they predicted the perspective landscape from another visual point (doll's position). Group IV: The subjects had the smile task as Group III except for verbalization. It was a kind of delayed memory task for Group I and II. The results of the interim test were as follows. The score of Group I was the best of the four. The score of Group I was significantly better than that of Group II. Immediately after the interim test, the post-test (the same task as the pretest) was administered. Its results of it were as follows. Among four groups, only Group II showed significant progress from the pre-test to the post-test. It was interesting that only Group II that had no observational effect showed significant progress in the post-test,. In general, through the interim and post-test, verbalizing effect had not found, and there were no significant difference between Group III and Group IV. In conclusion, it was most effective for the child's experience to remove himself for 90or 180 degrees and confirm the sight by their own eyes in the interim test.