Abstract Lightning information indicates the intensity and the development of severe convection. The characteristics of lightning activity and charge structure of a squall line over Beijing on 13 June 2010 is analyzed by using the SAFIR3000 lightning detection data, Doppler weather radar and precipitation data. The results show that the lightning radiation sources were majored in the convective leading region with a high reflectivity in front of the squall line, and the number of lightning radiation sources gradually increased in the back of stratiform region only at the dissipating stage. The correlation coefficient between the total lightning and convective precipitation is found to be 0.82, and that of intra-cloud lightning and convective precipitation is 0.76. It is inferred that the lightning is closely related to dynamical and microphysical process of the squall line. According to the lightning radiation distribution, the charge structure of squall line is also discussed. At the mature stage of the squall line, the lightning radiation sources presented two-layer with the upper level centered at 11 km and the lower level at 6 km, respectively. Based on the bidirectional leader of lightning propagation and the assumption of VHF source density maxima being most likely associated with positive charge region, it is concluded that the squall line was characterized by a tripole charge structure with a middle charge region between the level of 8 km to 10 km and two positive charge regions in the level of 10 km to12 km and 4 km to 7 km above the ground, respectively.