Abstract: The definition of the web server performance is given first in this paper. And then discusses is how to work out the key issues of the web server performance from the three levels of architecture: the application workload, the server software and the server hardware. By comparing the different testing tools, SPECweb99 is chosen as the workload. By using the exploring way, the testing times are greatly decreased. And the bottleneck that affects the system performance is found out by covering the other kinds of HTTP requests: the handling of the dynamic request CAD GET. By tuning its percentage in the dynamic request, its influence on the response time of different files with various length is analyzed and then the corresponding code is optimized. When this scheme is applied to Dawning 3000 super server, the test data shows that 2 times performance improvement can be expected.