Using the data from the South China Sea Monsoon Experiment (SCSMEX) in 1998 and the regional kinetic energy budget equation, the budgets of the total and turbulent kinetic energy were calculated before and after the onset of monsoon over the southern and northern South China Seas respectively. The results show that the kinetic energy over the northern part mainly formed at the upper levels and dissipated by friction, while the kinetic energy over the southern part mainly dissipated at the upper levels and the friction acts as the sources of kinetic energy. The turbulent kinetic energy was also chiefly produced at the upper levels. The kinetic energy was transported to adjoining areas during this period.