In this paper, about 100 typhoon processes are analyzed on their satellite cloud maps' characters, and the cloud top black body temperature (TBB) of 10 typhoon processes are calculated. They are associated with 10-days average sea surface temperature distribution to study the features and conditions in the early stage of typhoon formation.Some conclusions are found as follows:If a tropical cluster with a vortex structure has following conditions:1. One or more long outer cloud bands of more than 500~ 100...