Abstract: The spatial data quantity of different formats for a map are compared by experiments.Storaging map by raster format,its spatial data quantity is equal to the other of same size map if not be compressed.If only be compressed,the raster format data quantity has relation to chart speckle area size..bmp file spatial data quantity is the most large in several raster formats,.jpg file and.gif file data quantity are less.But storaging map data quantity by vector format has relation to spatial data attribute..e00 file spatial data amount is the most large in several vector formats.