A highly efficient embedded Web publishing system in substations is designed to improve the application functions and response speed of the Web server， and simplify the data sent back from the server-side， bringing about a better adaptability for frequent data updates. In the system， the JavaScript code is sent to the client at the first connection to set up the AJAX（asynchronous JavaScript and XML） engine to obtain the asynchronous message from the server-side through the callback function and completes local fast refreshing of the Web page by calling the application programming interface（API） of the document object model（DOM）. With data publication based on the XML document format， remote monitoring of the substation is realized by providing information to the browser by local refreshing in the asynchronous mode; the unified XML documents are submitted to various information systems in the electric power data network for the realization of substation data sharing.