We know that Line and polygon can be expressed by their feature points because point is the fundamental feature in vector GIS. Because only digital accuracy of point data is defined in the International Geographic Information System(GIS) data quality standard system

so this paper defines the visual indexes of point ellipse

line error band and polygon error donut to assess effect scope of their positional uncertainty according to the probability that the feature points dropping into their error ellipses based on the error ellipse expressing the positional uncertainty in surveying and mapping

we wish to richen and perfect the system of GIS data quality standard system and to control the data quality of many GIS databases to a higher accuracy.