Pot and incubation experiments were carried out to study effects of soil moisture and phosphorus (P) application on soil available P content in a new rice cultivation system, i.e. aerobic cultivation of rice crop. In the experiments, significant effects were observed of both soil moisture and P fertilization, and more of the interaction between the two, on soil available P content, and on biomass and P uptake by rice, as well. The content of soil available P in the tested soil increased with increasing soil moisture and P application rate, but decreased with growth of rice. Biomass and P uptake of rice increased with increasing P application rate and growth period of the crop, and peaked when soil moisture was moderate in content. Therefore, when the rice field is ensured soil moisture being 80% of the soil saturation moisture capacity and conventional N and K input, P application at 67.5 kg hm^-2 is adequate to meet the P requirement of rice for growth in aerobic soil.