A preliminary study has been conducted to test the effectiveness of the stepwise canonical discriminant approach to making spatial discrimination of salt-affected soil surfaces, using the Landsat TM data taken in the middle reaches of the Heihe River, China. We regard a saline area as being composed of salt-affected patches differ in degree and try to make discrimination of salt-affected soil surfaces by stepwise canonical discriminant approach. Five indices (B4, Wetness, SI, NDSI, Fe2O3) were selected as discriminating variables, and two canonical discriminant functions (y1, y2) were determined for the three groups using these five discriminating variables. When group centroids and individual cases were plotted on the plane determined by two canonical discriminant functions y1 and y2, the groups were quite distinct and their centroids were well separated. These results suggest that the stepwise canonical discriminant approach is promising for spatial discrimination of salt-affected soil surfaces.