A 2-D load spectrum program based on rain-flow counting method was compiled in Matlab environment. The program was used not only in statistical treatment of load time history of motor propulsion system on hybrid electric vehicle (HEV) and getting rain-flow matrix, but also in hypothesis test for both amplitude and mean value distribution. 2-D distribution function was obtained after the independence and relevance tests of the amplitude and mean value. 2-D load spectrum was set up for traction motor propulsion system on HEV used in bench experiments.