The climatic change in Tianjin and its influence on grain production are studied by using the temperature and rainfall data during 1932—1989. The results show that the warming in Tianjin coincides with that in the Northern Hemisphere, and the warming in winter is more obvious. The rainfall in Tianjin was increased in spring and early summer, while decreased in mid summer during the global warming period of 1980s. The warming climate in 1980s was very favourable to the yeild of winter wheat and maize, but unfavourable to the soybean in Tianjin. The drought climate in 1980s was unfavourable to the growth of rice, either in sown area or in yield per unit area.