Abstract: Taking the tobacco planting soils in Sanmenxia of Henan Province as study objects, five factors which closely related to tobacco growth were adopted to evaluate the soils' suitability for tobacco planting with grey cluster analysis. The results showed that the tobacco planting soils in Mianchi,Shanxian and parts of Lushi counties possessed higher suitability,and the suitability of some tobacco planting soils in the south of Lushi County was lower. In grey cluster analysis,each index is weighted separately, the resulted conclusion would be more objective and reasonable comparing with traditional methods.