Effect of elevated atmospheric CO₂ on available C, N and P in the soil under winter wheat growing through FACE(free air carbon dioxide enrichment)system was studied, through comparison between FACE and the ambient in content of available C, N and P in the soil at different wheat growing stages. The results showed that elevated CO₂ decreased the content of soil available C in the 0~5 cm soil layer before the heading stage, but increased at the ripening stage. The effect of elevated CO₂ on soil available C differed between rice and winter wheat. Under LN and NN treatments, elevated CO₂ increased soil available N by 17.2% and 18.9% at the tillering stage, but decreased by 9.8%-63.0% at others stages and the most at the heading stage, up to 63.0% and 50.4%, respectively. The results indicate that it is necessary to increase N fertilizer application level to both rice and winter wheat growing under elevated [CO₂] condition. The content of soil available P increased due to elevated [CO₂], more in the LN treatment than in the NN treatment. The study indicates that growth of winter wheat will not restricted by soil P under elevated CO₂ condition.