Abstract The purposes of this study are: 1. To understand the test results of the CA 6-12 subjects in Taipei area by the Benton Visual Retention Test (BVRT); 2. To compare the BVRT scores between the differential ages, sexes and IQ levels of the normal children and the MR children; 3. To know the effect of the visual retention funtion training. In this study, 6459 normal children and 210 MR children were tested by the BVRT, and 18 MR children were trained in the retention activities. The results of this study are: 1. The BVRT scores of the normal children are increased with the CA level, but there are not significant differences between the scores of male and female children group (p>0.05). 2. The BVRT scores between the male and female children have high relations (p<0.05). 3. The BVRT scores of the normal children are better than those of the MR children (p<0.05). 4. For both normal children and MR children, the BVRT scores are increased with the CA; high CA children's scores are better than those of the low CA children. 5. In BVRT, mistakes made by the MR children group, from high to low percentage, are: (1) distortions (2) omissions (3) size errors (4) perseverations (5) rotations (6) misplacements (7) additions The visual retention function of the higher CA's MR children are better than that of the lower CA's MR children. 6. The BVRT post-test scores of the MR children are better than the pre-test scores through the visual retention function training. There are significant differences between the pre-test scores and the post-test scores (p<0.05).