Abstract: Long-time series of Doppler radar measurements from June to September of 2009-2013 have been used to investigate the climatological distribution of convection in the warm season at Nanjing. Result indicate that:(1) In the warm season, there is an obvious areal distribution characteristic of convection at Nanjing. July and August are the periods with most active convective activities. High frequencies of large convective storms are found in the eastern part of Nanjing. (2) Distribution features of convective storms vary with different scales and upward extensions of the storms. The high frequency center is more distinct for large and deep convective storms. (3) The vertical structure of the convective storm varies with month, and convective storms in July and August are the strongest. (4) The frequencies of convective storms at different scales and upward extensions have a clear diurnal variation with multi-peaks. The primary peak occurs in the early afternoon. Similarly, the diurnal variation of the storm frequency is distinct in all the months with single- or multi- peak features.