In order to understand the effects of future climate change on growth characteristics and yield of summer maize, three CO_2 concentration(380,550,750 cm~3/m~3) treatments and two night temperature increase (0,2 ℃) treatments were conducted in six different Open Top Chamber (OTC) and heating devices with Zhengdan 958 as material. The plant height, SPAD (soil and plant analyzer development) value,LAI (leaf area index) and above ground biomass during jointing,tasseling and maturing periods were measured. In addition,maize yield and yield components were also determined. The results showed that the plant height,SPAD,LAI and above ground biomass all increased with the increase of CO_2 concentration. The plant height, LAI and above ground biomass increased when night temperature raised during the jointing period; however,the three indexes decreased at the tasseling and maturing periods. The yield and yield components increased with the increase of CO_2 concentration,and decreased under night warming conditions. When the night temperature was increased by 2 ℃,550 cm~3/m~3 CO_2 could counteract the negative effect on biomass and yield produced by night warming.