Our current studies on the effects of wind shear, entrained bubbles,dispersing droplets, swell and rainfall on turbulent mixing and mass transfer at the air-water interface will be introduced. The CO2 transfer experiments were carried out in two wind wave tanks and an open-channel with a rain chamber, and direct numerical simulation was complementally used to better understand turbulence structure and mass transfer mechanism at the air-water interface. The experimental and numerical results show that the mass transfer coefficient on the liquid side is better correlated with the free stream wind speed than the wind speed at the elevation of 10m above the interface. The effect of entrained bubbles due to wave breaking is significant for seawater in the high wind speed region, whereas the effect of dispersing droplets in the gas flow is negligibly small. The swell in the same direction as wind acts to reduce the mass transfer. The rainfall locally promotes the turbulent mixing and mass transfer across the air-water interface, and the promotion effect of heavy rainfall corresponds to that of the high wind speed of about 15m/s in a wind wave tank. However, the contribution of rainfall to the global mass transfer is small, compared to the effect of wind shear.