Based on the OH radicals, ozone, water vapor observation data of microwave limb sounder(MLS) sensor from 2005 to 2009, the spatio-temporal distribution of OH radical and its association with ozone and water vapor in the stratosphere and mesosphere were analyzed. The results indicate that the OH radical concentration has obvious disparity in different latitude area, and there are obvious yearly periodic variations. OH radical concentration of global high-level quarter changes significantly. In the upper stratosphere, OH radical concentration is mainly influenced by changes of solar radiation and ozone concentration. In the mesosphere, OH radical concentration is closely related to the water vapor concentration variation.