The occurrence of rapid intensification (RI) of tropical cyclones (≥10 m/s in 12 h ) in the offshore of China is examined to determine the geographic and seasonal variation of these events. Eighty-four cases of rapid growth process during the period 1949~1990 were selected to study climatological characteristics. The statistical results reveal that the majority (82%) of RI occurs in July through October. Most of RI are associated with sea surface temperature ≥28℃. The changes of wind speed and central pressure of RI as well as the rate of intensifying are also estimated.