Tomato (Lycopericon esculeutum Mill) was grown in manual gas chamber and winter plastic greenhouse in this research. Firstly, we wanted to know the harmful effects of the combination of high UV-B irradiation dose and doubled CO2 on tomato. Secondly, we expected to find the best way to improve the output and quality of tomato with the combined effects of low UV-B irradiation dose and doubled CO2.In the first part, we choosed a high UV-B irradiation dose about 8.40 kJ.m-2.d-1 and doubled CO2 to co...