The loading capacity is an important measure of ebusiness software. Three typi cal loadtesting methods are data statistic and estimation of online system, progra m calculation, testbased evaluation. Now, people pay more and more attention t o the testbased evaluation. This paper demonstrates this evaluation method by an example a small ebusiness system, and its load ability is analyzed in d etai led. The results show that the evaluation aiming to optimization can get the bes t forecast load data by using load testing step by step. And on the process of l oad ability evaluation, we should choose reasonable measures carefully according to main functions of the underevaluationsystem. 