Abstract:A dust event which occurred in Shanghai during May 1~4, 2011 was investigated. The main features of dust transportation as well as formation were preliminary examined using data of atmosphere extinction coefficients and vertical profiles retrieved from the ground-based Micro Pulse LIDAR (MPL_4B), synoptic meteorological factors, aerosol concentrations and satellite remote sensing products. The results show that the dusty day on 1st May was mainly influenced by PM2.5, while the dusty day during May 2~4 was influeced by returning process of dust, in which the PM2.5 concentration decreased compared to that on 1st May. Dust from remote source, vertical wind distribution, and atmospheric stratification change provide favorable conditions for the formation and maintenance of the dust event. Moreover, as to the role of aerosol in atmosphere extinction, the scattering effect was more evident than absorption.