Abstract: The communication model between Web clients and their servers usually is characterized as the distributed transaction;and it is obvious that TCP can not support this kind of application efficiently,especially in the high speed network environments. The mechanisms and the policies on supporting Web applications are optimized and improved from the viewpoint of communication models,protocol overheads and parallelism granularity,and the support of Web applications by Xpress Transport Protocol is proposed and analyzed. The interactions and compatibility with other schemes are also considered.