The purpose of the study was to study the effectiveness of two concept learning models, prototype model and classical model, on acquisition and retention of concrete social studies concepts. The effectiveness was investigated by immediate post test result and retention test results. The subjects were 1/7 6th graders of an elementary school in Seoul. Two classes each were randomly assigned to two experimental groups. The concept learning materials were developed by the researcher, and checked for content validity by four elementary school teachers. The learning materials were on " Sea and Strait" All the learning materials were in written form. The subjects in each group studied the materials for 30 minutes. The immediate and retention test materials were adapted from Yoho's experiment(1987), and Unlocking Social Studies Skills(980), and revised by the researcher for the subjects of this study. The problems to be tested were as follow. 1. Will the effectiveness of the prototype model be superior to the classical model in acquisition of concrete social studies concepts? 2. Will the effectiveness of the prototype model be superior to the classical model in retention of the learned concepts? Pretests were administered for 10 minutes, followed by 30 minutes' learning of two kinds of the written learning materials. Post tests were given immediateley and retention tests were given in a week for 10 minutes. One-way Anova was performed to analyze each of the pretest, immediate post test and retention test results of the prototype model group and classical model group The results were as follow. 1. There was no statistical difference between the immediate learning outcome of the prototype model group and the classical model group 2. The retention test score of the prototype model group was higher than that of the classical model group.