During the past 12 years, more than 200 videosondes have been launched into monsoon clouds from 13 different locations in east Asia. Storm precipitation mechanisms have been investigated using videosonde data giving hydrometeor type in clouds monitored by radar. At each location, different monsoon cloud systems develop in unique synoptic disturbances. In the east Asian monsoon area, rain is divided into three different regimes with respect to the precipitation mechanism occurring in each. The frozen drop process (frozen) occurs over the open ocean, and the ice process (cool) occurs over the inland desert. Over a maritime continent, both frozen and ice processes (mixed) are held. Heavy rain is produced by extensive growth of graupel and frozen drops in the convective center near the melting level. Further raindrop growth at the lower levels leads to very high rainwater content in the "mixed" region. Number concentrations of ice crystals and graupel (frozen drops) were very low over the open ocean where lightning frequency is also low. In east Asia, ice crystal and graupel (frozen drops) concentrations are closely related to lightning activity.