Abstract: The impact of high temperature and high CO₂ concentration on crops is studied in artificial chambers. The results show that the high temperature and high CO₂ concentration would accelerate crop growth and development,shorten the growth period,increase the photosynthetic rate,decrease the transpiration rate,and increase the stomatal resistance. At the same phenophase,the leaf area and biomass of leaf, root,stalk would decrease because of insufficient growth. The impacts on yield components of different crops are different,spikelet numbers and grains number is decreased in wheat,hundredgrain weight decreased in corn. The high temperature and high CO₂ concentration change the contents of trace elements in leaves.