Abstract: The traditionally used parameter for accessing the surface such as surface roughness has a very limited value in relating the functional properties of bearing and lubricant retention capabilities to the surface of rolls and steel sheets. This paper proposed some functional characteristic parameters of 2-D profiles and 3-D surfaces and presented their calculating methods. By comparing with surface roughness and analyzing the surface of electrical discharge textured rolls with these parameters, it is proved that these parameters more concretely and exactly show the functional properties of surface topography.