The performance of information retrieval on the Web is heavily influenced by the organization of Web pages, user navigation patterns, and guidance-related functions. Having observed the lack of measures to reflect this factor, this paper focuses on an approach based on both structure properties and navigation data to analyze and improve the performance of Web site. Two types of indices are defined two major factors for analysis and improvement — "accessibility" reflects the structure property to measure how easy the user can access the pages and "popularity" implies the navigation data primarily based on the log statistics. The accessibility and popularity (A-P) plot serves as a compass for the Web designer to get an overview of current performance status and explore in the possible directions for improvement to balance the design anticipation and navigation expectation.