More and more regions, departments and organizations in China carry out corruption risk management during the previous couple of years. However, there is a lack of scientific approach to the grading of corruption risk evaluation empirically, thus limiting the effectiveness of corruption risk management. Essentially, corruption risk-level and corruption degree are more or less the same concept. Traditionally, there are two general ways of corruption measurement: objective and subjective approaches. Since different kinds of flaws exist in these two approaches, lack of accurate corruption measurement is unavoidable. According to the latest experience of measurement from Transparency International and Hong Kong, based on the revision and discussion of the current corruption degree definition, as well as the theoretical study and analysis, the author proposes an innovative approach which provides a more accurate measurement, behavior-based measurement. This new methodology is applicable to the corruption risk-level assessment thus making contribution to the scientific corruption risk management currently undertaking in China.