Abstract: Field experiment shas been carried out with desig ned OTC-lopen topchamber for nine years continuously and a set of credible experiment data have been collected.With these data,the effects of double CO2 concentration on biomass,yields and quality of soybean,winter wheat,cotton,maize,sprint wheat and millet were analyzed.The results show that double CO2 has positive effects on biomass and yields of these sixcrops and may has favorable effects on quality of winter wheat,cotton and miller,butnegative effects on quality of maize and few effects on soybean.It was analyzed also the effects of double O3 on biomass,yields and quality of the winter wheat,rice,rape and spinach.The results show that doubled O3 has negative effects on biomass of these 4 crops and yields of winter wheat and rice.Crude proteins and 17 kinds of amino acid in seed of winter wheat and rice are increased.The effects of doubled CO2 and O3 interaction on biomass,yields and quality of soybean were investigated.Biomass and yields of soybean are increased,which indicates that positive effect of CO2 is more than negative effect of O3.Atlast,the assessment of effects of double CO2 and O3 on biomass and yields of winter wheat with the crop growth model in the way of numerical simulation was also made.