In　order　to　enable　manufacturers　to　get　error　compensation　service　by　internet　to　improve　machining　precision,　this　paper　combined　error　compensation　with　computer　network　and　researched　Web-based　error　compensation　system.　The　Web-based　error　compensation　system　used　B/S　mode　and　three-tier　structure　and　the　Web　server　communicated　with　the　users,　the　application　server　did　the　error　compensation　algorithm　and　the　database　server　stored　and　accessed　all　of　the　data.　Experiments　show　that　the　Web-based　error　compensation　system　can　run　steadily　and　the　expectation　has　gotten.