The purpose of surface matching is to determine transformation parameters without known corresponding points for two data sets of spatial point coordinates obtained with use of different sensors. Instead of different features such as points of interest, lines, surface patches in the TIN (Triangle Irregular Network) or DEM model are used. The paper presents an approach of using inertial moments of TIN models generated from two data sets of same terrain for surface matching. The inertial moments could easily be calculated for each triangle in the TIN using formulae given. Three moment invariants/,./,,,,"/""'' that are used as the features of high level for surface matching are defined.