The effects of elevated ozone (O3) concentrations on the growth and C, N, S allocations of rice (Oryza sativa L., 3694 Fan) were investigated with Open-top chambers (OTCs) in situ in Jiaxing, Zhejiang province. Four treatments with three replicates for each treatment were deployed: charcoal-filtered air (CF, 10 nL?L-1), unfiltered air (NF, 40 nL?L-1), and charcoal-filtered air with ozone addition (100 nL?L-1 for O3-1 and 150nL?L-1 for O3-2). Rice was planted on May. 26 then transplanted into the OTCs on Jul. 4 and harvested on Nov.12, 2008. The ozone exposure started on Jul. 25 and ended on Oct. 19, 2008 at 9:00-17:00 (Chinese standard time) except raining days and the actual exposure was 69 days. We determined the component biomass (root, stem, foliage, panicle) of rice on Jul.27, Aug.14, Sep.18, Oct.17 and the C, N, S concentrations in root, stem, foliage, panicle and grain of rice when the rice was harvested. The main results showed that: 1) At the beginning of the ozone exposure, there were no significant differences in the biomass of rice components among the treatments. However, in maturing stage, the root, stem and panicle biomass of rice, as well as the root-shoot ratio and plant height, were significantly lower under the elevated ozone concentrations. During the whole experimental period, the differences in component biomass and plant height of rice between CF and NF treatments were not significant. The percentage of dry matter of aboveground biomass increased under elevated ozone concentrations and plant height was more sensitive to ozone than the aboveground biomass, which indicated that ozone stress might have much more effect on the cell elongation than on the cell division; 2)Under O3-1 and O3-2 treatments, the C concentrations reduced in root and stem but increased in foliage, which meant that the C allocation to foliage increased but reduced to root and stem under elevated ozone concentrations; 3) The N concentrations in all components of rice increased and it might be a adaptive strategy to resist the ozone stress. The C/N ratios reduced in all rice components under elevated ozone concentration and it revealed that the vegetative growth was inhibited under ozone stress; 4) The S concentrations in stem, foliage and panicle increased in O3-1 and O3-2 treatments, which would enhance the antioxidant capacity of rice under ozone stress. All the results indicated that elevated ozone concentrations had significant unfavorable influence on rice growth and it led to the obvious changes in the allocations of C, N and S in different rice components.