Abstract: Flux exchange coefficients including drag coefficient (CD), sensible and latent heat flux exchange coefficients (CH and CE) are important paramete rs for fluxes computation when the bulk algorithms and routine observations are used. The comp utation results vary with the experiments over different regions, weather and se a states. The data of the third SCS air-sea fluxes observation experiment from 24 April to 20 June 2002 are used in this paper. Momentum, sensible and latent heat flux exchange coefficients before and after the onset of the SCS southwes t monsoon are estimated using the eddy correlation and TOGA OCRES 2.5b algorithm s. The features of these coefficients and their relationship with other meteorol ogical parameters are also discussed. The results indicate that these flux excha nge coefficients changed significantly with the variation of wind direction, win d speed, cloud, precipitation, humidity and sea state before and after the onset of SCS southwest monsoon. Under the neutral condition, the momentum exchange co efficient（CDn ）varied from a smaller value before to a large value after the onset; and the sensible （CHn ）and latent（CEn）heat exchang e coefficients were not sensible to the synoptic change. The momentum exchange coefficient was mainly affected by wind speed, but the association between the both differed with wind speed size. The sensible heat exchange coefficient was positively proportional to the air-sea temperature difference and negatively to air temperature. The latent heat exchange coefficient had close correlation with wind speed, when the w ind speed exceeded＞12 m/s, C E gradually approached to a stable value. Beside, when the air-sea temperature difference was less than＜ 2℃, CE increased with the t emperature difference; and when it exceeded＜ 2℃, the relationship between CE and the temperature difference turned weak. The above relationships between the coe fficients and meteorological parameters could be expressed with simple linear relation or polynomial fitting.