The purpose of this study was to investigate the sixth grader's political knowledge. Research design and instrumentation were based on politial system theory. The theory was used to anlayze social studies textbooks and develop the political knowledge test. Five hundred and four sixth graders from elementary schools in Taichung city were selected as the subjects. The data were collected through the test. The major findings were summaried as follows: 1. On the whole, the sixth graders scored a little higher than the passing mark on the political knowledge test. 2. The concept of the sixth graders' political knowledge including political value, political structure, policy and political process had higher scores than their political concepts of government official, Chinese culture, political norm and political symbol. Implications of these findings were inferred as follows: 1. The contents of social studies have to be arranged to catch up with the change of social environment. 2. The limitations inherent in schools have to be noticed when elementary teachers teach their students the political concepts.