The content of water vapor in atmosphere is very little and the volume ratio of moisture to air is about 0.1%～3%, but water vapor is the most active molecule in atmosphere. Due to advantages of the high resolution, wide range and highly automatic operation, the Raman lidar has become the useful newstyle tools to measure water vapor. The new mobile home Raman lidar developed firstly by Anhui Institute of Optics and Fine Mechanics, the Chinese Academy of Sciences in Oct. 2004, is introduced as well as its structure and specification. Process method of the lidar data is described. The practical and comparative experiments were made over Hefei city. The measurement results show that this lidar has ability to gain profiles of water vapor mixing ratio from surface to the height of about 8 km in nighttime. Meanwhile, the measurement of water vapor in daytime has been taken, and the profiles of water vapor mixing ratio in boundary layer have been detected.