A typical dust event that passed over Dalian (121.63°E、38.90°N) on Apr. 28, 2 005 has been observed by a micropulse Lidar (MPL) in the framework of ChinaK orea Dust Monitoring Program. It is found that the dust layer located in 0～5km above the ground level is more than 5km in geometrical depth. Some typical ext inction coefficients of atmospheric aerosol distribution were obtained by analys is of Lidar measurements from this dust event. Vertical distribution and develop ing characteristic of aerosol extinction coefficient were analyzed and discussed in this sanddust process. This study shows that this dust air mass was transp orted to Dalian at long distance. The stable atmospheric stratification plays an important role in the diffuse and fallout of aerosol.