GIS are closely related to mathematical cartography, as they work with spatially coordinated data. Practical course in mathematical cartography should meet the requirements of time and include tasks involving the use of modern GIS technologies. The functionality of GIS packages allow you to easily create maps in a given map projection, draw graticules and measured grids, perform dimensions on maps. This article is devoted to the research of map projection properties on the basis of GIS technologies in a practical course of mathematical cartography. The focus is on visual way to display local and regional distortions on maps. To create lines of equal distortion should use special software tools that allow to build digital models of surface distortion distribution directly on formulas or be interpolated both discretely located nodal points and isolines.