Tropical cyclones are among the most destructive natural hazards on the earth, causing serious ecological and human damage. Tropical cyclones are one of the most fascinating weather phenomena for many people, not only because of the vast amounts of serious ecological and human damage they cause, but because of the great scientific challenges they pose to us as a complex atmospheric system. Tropical cyclone genesis, although an area with many researches, remains a highly debatable and unresolved field. Existing theories have not easily explained the relative rareness of tropical cyclone formation. The South China Sea (SCS), which is a large semi-enclosed marginal sea in the western Pacific Ocean, is one region where tropical cyclones occur frequently. Compared with tropical cyclones in other regions, there is relatively little work on tropical cyclone genesis over the SCS.This book presents the researches investigating several issues pertaining to tropical cyclone genesis over the SCS, one region under the significant influence of monsoon. Analyses of satellite observations and reanalysis datasets plus numerical simulations are applied to investigate the mechanism of tropical cyclone genesis over the SCS. The SCS provides us one perfect experimental field to study how monsoon impacts tropical cyclone activities.