This study describes an experimental investigation on coherent structures and corresponding gas transfer phenomena beneath the air-water interface in wind-induced open-channel flows by using laser Doppler anemometer (LDA) with a wave-gauge sensor. In this study, the organized motions are investigated in detail by the linear filter technique and the time-frequency analysis using the wavelet transform, by which the wave-induced linear fluctuations are separated from the whole velocity fluctuations. As the results of experiments, it is shown that the coherent motions are observed significantly beneath the free surface due to the air-sheared flows, and that the gas transfer phenomena across air-water interface are governed by the organized motions beneath the water surface. It is pointed out that the main characteristics of coherent motions near the interface in these flows are similar to those of turbulent boundary layer with non-slip wall, and that the dependency of the gas transfer phenomena against the friction Reynolds number can be explained in terms of the frequency of the organized motions. This is because the high frequency motions are superior in the organized motions.