Abstract: Through the analysis of typical MapInfo point and line(area) buffer construction examples,the problem of MapInfo line(area) buffer construction model based on map projection plane is proposed.Analyzing and validating its reason,the improving ideas and methods are given out: constituting line(area) buffer construction model by MapInfo point buffer construction model and convex hull construction model;constituting line(area) buffer construction model based on the Earth ellipsoid.Not only an idiographic method is provided for MapInfo users to improve the accuracy and reliability of spatial analysis,but also users are reminded not to abuse the buffer analysis tools.On the other hand,this will put forward a good reference for the new edition of MapInfo system and other GIS developers.