Abstract: The middle of the farming-grazing zone of the northern China is a typical belt region with the ecological frangibility, but is an important naturally and ecologically protective barrier for the North China Plain. This paper presents the results of the temperature and precipitation changes during 1951-2005 over this region. It is concluded that there was an increasing trend of the annual mean temperature at a growth rate of 0.4℃ per ten years, and the increment in temperature was the highest in winter, followed by spring, summer and autumn. There was a decreasing trend of annual precipitation from 1950s to 1960s and an increasing trend from the 1990s to the present. Precipitation in summer showed a similar trend as the annual precipitation, and precipitation in autumn and winter no evident change trend. The extreme events have more frequently happened since the 1990s because the high temperature and dry weather continuously increased, which is detrimental to the development of agriculture in the study area.

Key words: farming-grazing zone, climate change, temperature, precipitation