Abstract: The SCSMEX is a joint at mospheric and oceanic experiment by international efforts, aim at studying the onset, maintenance and variability of the South China Sea (SCS) summer monsoon, thus to improve the monsoon prediction in Southeast and East-Asian regions. The field experiment carried out in May) August, 1998 was fully successful, with a large amount of meteorological and oceanographic data acquired that have been used in four dimensional data assim ilations by several countries, in order to improve their numerical simulations and prediction. These datasets also are widely used in the follow-up SCS and East-Asian monsoon study. The present paper has sum marized the main research results obtained by Chinese meteorologists which cover six aspects: (1) Onset processes and mechanism of the SCS summer monsoon; (2) development of convection and meso-scale convective systems (MCSs) during the onset phase and their interaction with large-scale circulation; (3) lowfrequency oscillation and teleconnection effect; (4) measurements of surface fluxes over the SCS and their relationship with the monsoon activity; (5) oceanic thermodynamic structures, circulation and meso-scale eddies in the SCS during the summer monsoon and their relat ionship with ENSO events; (6) numerical simulations of the SCS and Eas-tAsian monsoon.