The life cycle of convective activities in the tropical Pacific is studied by analyzing the time sequences of different types of clouds. Cloud is classified (Inoue,1987) using the split window data from GOES-West. Three types of clouds can be identified, thin and thick cirrus cloud that contains mostly ice particles, and optically thick cumulus type cloud. Preliminary results indicate that the amount of cumulonimbus cloud increases very rapidly at the developing stage of convection, followed by a moderate increase of thick cirrus such as those found in anvils. At the decaying stage, cumulonimbus disappears, thick cirrus decreases, and thin cirrus reaches its maximum before it decreases gradually.