In this paper, we discussed deeply the bepuzzlements which are faced with when GIS resolve these problems. Based on the analysis of necessarily spatial data of GIS, four types of spatial relation data were defined: location, adjacency, nearness and influence. Between each type of data and its next one, the latter has more quantity of data than the former. It will be a very difficult work, and is the source of data problems such as "not prepared when needed" and "prepared but never used", to organize all these data comprehensively and apparently. From all above, as an idea of resolving these problems, the feasibility and features of Map Algebra were discussed.