Explosive cyclones, known as meteorological “bombs”, are defined as a cyclone whose central sea level pressure decrease normalized at 60°N is greater than 1 hPa per hour. They frequently occurs over the vast ocean in cold season and usually causes serious losses of life and property due to the extremely bad weather related to their rapid intensification. Many previous studies focused on the climatology, spatial-temporal structures and developing mechanisms of explosive cyclones. During the past years, many significant progresses had been made on study of explosive cyclones, but there are still some questions which were not solved. In this paper, the previous researches on explosive cyclones are reviewed and some problems unsolved are indicated, aiming to have some enlightenment for future researches on explosive cyclones.