This study was carried out to investigate optimum wind velocity for growth of Pleurotus ostreatus. In the chamber experiments, the divergence of pileus was 63° in 0.3m/s, and it showed the tendency that the more the air velocity was increased, the more the divergence became small. And the ratio of commercial yields was 96% in the air velocity of 0.3m/s. In the cultivation room experiments, the divergence of pileus was 64° in 0.3m/s, and it was the tendency that the more the air velocity was fast, the more the divergence became larger. And the commercial yields was similar to the trend of the chamber experiment as 94.8% in 0.3m/s, and the quality characteristics of the fruit-body showed the uniform quality in comparison with other treatment because the standard deviation of the size of the pileus, etc. was the lowest in 0.3m/s like the chamber experiment.