CS(Customer Satisfaction) has been focused as one of the most important factors in business administration nowadays. After measuring and evaluating CS level, most companies are performing many activities to improve it. Therefore, it is very important for driving CS management to measure the exact CS level. When measuring CS level, however, CSI(Customer Satisfaction Index) is changed by the computing method of importance for CS factors, and the corporate strategy is changed by CSI. In this research, some computing methods are reviewed and compared through the analysis of real data. Also, a hybrid computing method for CSI is proposed and compared it with other methods.