The government Websites, as the main content of e-government construction, attract much concern from lots of scholars, governments and research organizations. The evaluation on their performances has important effect to guide and inspect their construction. In order to remove the objective fundamental conditions' influence on the evaluation of their performances, the paper proposed the concepts of reference performance, current performance and performance with binary relative evaluation method, and built the binary relative performance to measure the extent of the government's subjective efforts in the construction of government Websites. The paper evaluated the China provincial government websites with the binary relative evaluation method. The evaluation result showed the binary relative performance had incentive to all the governments and made the evaluation fairer.