From Mar. 21 to Apr. 19 in 2011, atmospheric observations with mobile Doppler wind lidar at Beijing observatory are operated by China Meteorological Administration. Atmospheric boundary layer is observed and analyzed by the gradient of lidar range-corrected signal. The processed results of lidar observation data indicate that the average mixing layer or surface stable boundary layer height is (1.44±0.75) km at 800AM and (2.23±1.13) km at 800PM, the average atmospheric boundary layer height is (2.88±0.92) km at 800AM and (3.37±0.82) km at 800PM, respectively. Compared with the gradient of potential temperature and relative humidity of synchronous radiosonde, the correlation index is as much as 94%, which shows good consistency with lidar.