This paper considers experimental and theoretical study of a compressor blade steel (EI-961 grade), subjected to solid particle erosion. Material samples were cut from the first stage compressor blades and then tested in a modified wind tunnel, capable of mixing abrasive media into an accelerated airflow. Velocity of the abrasive stream vas varied and additionally abrasive powders with different average particle sizes were used. Erosion resistance was assessed in two ways: measurements of the sample mass degradation and investigation of the surface roughness change due to erosion. Moreover, data fitting was used to calculate approximate threshold velocities for the abrasive powders used in the tests. Incubation time concept was applied in order to obtain dependence of the threshold particle velocity on the particle radius and to perform theoretical analysis of the material's resistance to the solid particle erosion.