This paper is a comparative analysis, which mainly compares two education development level indicators of Average Years of Education (AYE) and Adult Illiteracy Rate (AIR). In China, AIR is influenced by elder illiteracy seriously. This article, firstly analyzes the problems of using AIR, and secondly introduces the indicator of AYE and compares the two indicators. Finally, points out the conclusion, that it should be using AYR to replace AIR to measure regional education development level. Thus, we could get the values which are more realistic and more reliable.