In this experiment, effects of some environmental conditions on the interfoliar and intercellular air spaces in rice plant body were examined. The following results were obtained. 1. Effect of cultural temperature on the volume of interfoliar and intercellular air spaces was nearly the same at 20℃ and 30℃. 2. The volume of intercellular air space did not change significantly between the densely-grown plants and sparely-grown ones, but the volume of interfoliar air space of the former was smaller than that of the latter. 3. The volume of interfoliar air space in the plants cultured under heavy manured with nitrogen was larger than that in control plants. Reversely, the volume of intercellular air space was small in heavy fertilized plants. 4. In both paddy and upland rice plants, the volume of interfoliar air space was larger in the plants cultured under the paddy field condition than those under the upland field condition. On the other hand, the volume of intercellular air space of paddy and upland rice plants was fairly larger under the paddy field condition than that under the upland field condition. 5. The volume of interfoliar air space was decreased with the duration of submersing treatment but the volume of intercellular air space increased. Interfoliar air space surrounding the shoot apex directly decreased with the duration of the treatment.