This paper is concerned with the wind velocity fluctuations measured both over the long periodic waves (superposed by much smaller wind waves) and over the wind waves only, in a wind-wave tunnel by using a linearized hot-wire anemometer. practically the spectra of those fluctuations and the cross-spectra between wind and waves were obtained by means of digital procedures.
　Wind velocity spectra obtained show a range of frequencies where the spectral density varies nearly as f-5/3 (f: frequency), and this range is extended to much lower frequencies than expected from Kolmogoroff's theory. Over the wind waves only, the wave-induced velocity fluctuations were found to have a considerable intensity at the lowest height, decrease fairly repidly with height and become almost negligible at the height of 15 cm. Over the said long waves the wave-induced fluctuations were only moderately with height and remained at the height of 40 cm as a dominant component of the spectrum. The wave-induced fluctuations were found to be nearly in phase with the dominant waves.