The aerosol measurement by micro-pulse lidar(MPL) system is taken in Nanjing Comprehensive Observation Base of China Meteorological Administration in the north suburb of Nanjing. The variation of aerosol extinction coefficient profiles and depolarization ratio profiles indicate that the depolarization ratio of aerosols in clear atmosphere, mist and water cloud have similar values, but the value of ice cloud depolarization ratio is larger than all of them. Nearly 50 times inversion results of experimental data during January to June in 2009 show that the depolarization ratio is concentrated between 0 to 0.05 when the height of cloud base is below 4 km. While the height is above 4 km, this value is almost between 0.05 to 0.15. The higher of height cloud base is, the higher of the probability of larger depolarization ratio values is appeared. Comparing the inversion results of summer mist and winter dust in 2012, the results show that dust appears obvious boundary, while the characteristics of mist boundary is blurred. Dust's outbreak and dissipate can be monitored by combining spatial distribution and temporal distribution of extinction coefficient with change of depolarization ratio. Comparing the results of MPL and CE-318 sun photometer, the optical thickness of both instruments measured is consistent with the trends of time.