In this chapter the ocean responses to tropical cyclone (TC) in the China seas are discussed. The powerful Kuroshio, mesoscale eddy activity, and complicated bathymetry in the area modulate the responses to the passage of TCs. Upwelling, entrainment and near-inertial oscillation trailed behind TCs are well simulated by ocean models. Sea surface temperature (SST) cooling caused by upwelling and vertical mixing is observed using satellite observations and three dimensional models. Observational and high-resolution model analyses are carried out to study the favorable conditions and relevant physical processes that cause the SST cooling. The result demonstrates that upwelling dominates vertical entrainment in producing the surface cooling for a subcritical storm. Further, surface chlorophyll-a concentration often increases significantly after TC’s departure. Upwelling and mixing bring nutrient-rich subsurface water to the sea surface, causing enhancement of phytoplankton bloom.