The purpose of this study is to provide developmental data of the performance of children between the age of 6 to 12 to verify the hierarchical order of acquiring the cognitive competencies and to identify whether differences in the performance between male and female tested in revised Loewenstein Occupational Therapy Cognitive Assessment (LOTCA). The test consists of six subtests designed to be representative of various cognitive abilities. The subjects were 60 normal children from age 6 to 12 were assigned to a group 1 from 6.0∼7.11, a group 2 from 8.0∼9.11 and a group 3 age 10.0∼12.0. We measured their cognitive-perceptual ability with LOTCA. The results were a progress with from 6 to 12 years in both and speed of performance. Male group showed better score than females in Shape Identification of Visual Perception, Logic Question of Thinking Operation, Attention And Concentration. The Females are better than males in Motor Imitation of Motor Praxis, Pegboard Construction and the performance duration, Colored Block-Design and the performance duration, Plain Block-Design and the performance duration, and The length of time taken. Several subtests except Visual Perception, Direction on Cs’ Body, Spatial Relation of Spatial perception, Motor Praxis, Two-Dimensional Model of Visuomotor Organization, ROC Unstructured, ROC Structured, Pictorial Sequence A, and Pictorial Sequence B of Thinking Operation, which are showed significant differences between age groups. With the above results, we conclude that LOTCA is an appropriate tool for occupational therapists to use in assessing cognitive-perceptual abilities.