This paper examines the Sahel climate and environmental changes. It is helpful to understand the environmental problems in China’s arid and semiarid regions. The severe drought has continued for about 30 years since the late 1960s. There are upward trends in Sahel rainfall since 1980s with the magnitude of +12%/10 a, and the rainfall in July September of 1999 is the highest since 1968. But the decadal mean of 1990s is also very low, there is no signal showing the end of the prolonged desiccation. Many factors show influence in Sahel rainfall, including sea surface temperature (especially over the Atlantic Ocean), land surface processes,global warming and human activities such as overgrazing. In some years, soil moisture interaction may play a key role but sea surface temperatures are the dominant control factor. Internal dynamics are shown to have little effect. Looking at the Sahel as a whole, human activities also show little contribution to the Sahel climate and environmental changes. Some studies found that there are abrupt changes during the middle 1960s for the rainfall in both Sahel and northern China. The rainfall changes in these two regions show strong connection, thus the studies on Sahel drought is helpful for understanding the causes of variations of rainfall over northern China.