Abstract: The lidar ratio (LR) is an important parameter and impact factor for the retrieval of aerosol optical properties using micro-pulse lidar. We analyze the vertical LR retrieved by the method of correcting micro-pulse lidar with aircraft observation using multiple-observation equipment during one clean case (December 10, 2016) and two pollution cases (November 15–18, December 16–19, 2016) in Beijing. PM_2.5 concentration was lower than 40 μg m⁻³,while PM_2.5 concentration was higher than 150 μg m⁻³, and visibility was lower than 5 km during the severe-pollution period. The first pollution case was characterized via high-altitude transportation. The vertical extinction coefficient profiles and aerosol optical depth (AOD) obtained by the iterative algorithm using the LR values were closer to the in-situ observation than those obtained by the single column average value. LR obtained from this method primarily varied between 19 and 76 sr in different periods. The results showed a small LR value and insignificant differences in vertical distribution during the cleaning period, and LR increased in height from 19 to 45 sr in the boundary layer during the first pollution case. During the second pollution case, LR presented little variation during the pollution-development period and later decreased in height from 70 to 20 sr at the boundary layer under the severe-pollution period, while there were slight fluctuations above the boundary layer. The vertical distribution of LR along the boundary layer is related to the source of aerosols, especially the regional transportation in the high layer, and regional dust transportation may significantly increase the LR. LR fluctuates due to the influence of large particles or strong absorbing particles above the boundary layer. The results showed that LR increased with the increase in the extinction coefficient at the boundary layer as well as relative humidity (RH) when RH was higher than 40%.