The feature of surface layer wind velocity profile and the roughness length determined by the roughness units over nonhomogeneous landform are analyzed by using fivelevel effective wind velocities measured by the 35 m tower measuring system in a neutral stratification atmosphere. The result indicated that: (1) The surface layer wind profile is in logarithmic distribution, with correlation coefficients greater than 0.985, and standard deviations about 0.04. (2) The roughness length is 1.25 m, but it will vary between 0.038-4.903 m when the condition of external fluid changes, which has a negative correlation with wind velocity perfectly, with a correlation coefficient -0.953.