In order to compare the interfoliar and intercellular air spaces in paddy rice plant and other several Graminae (upland rice, wheat, corn and sugar cane), this experiment was conducted. The following results were obtained. 1. In upland crops except sugar cane, the percentage of interfoliar air space against the cross section of plant body was greater than that of paddy rice plant. It was evident at the upper portion of plant body. 2. Percentage of the intercellular air space against the cross section of plant body, however, was the greatest in paddy rice plant; upland rice comes second; the least was other upland crops.