A fertilization experiment with 150 kg N x hm(-2), 250 kg N xhm(-2) and 350 kg N x hm(-2) was conducted on the free-air CO2 enrichment (FACE) platform at Wuxi of Jiangsu Province in 2001-2003, aimed to build a simulation model of dry matter accumulation and allocation of rice in FACE. Physiological development time and CO2 concentration were selected as the driving factor and the main affecting factor, respectively, and nitrogen application rate was introduced as the factor adjusting the dry matter accumulation and allocation in green leaf, stem and panicle. The results showed that with the increase of atmospheric CO2 concentration, the dry matter accumulation in above-ground part of rice increased remarkably, but the allocation index dropped in green leaf, changed little in panicle, while increased in stem at early stage and equaled to the CK at last. The model was tested with different experimental data, and the results indicated that the model had high fitting degree and preferable applicability and predictability.