The study of commodity buying and selling region distribution is one of the important contents in commercial geographical research. It is this paper that is mainly to explore the research method of this content.1. The location of commodity buying and selling bases can be decided by the proportion of commodity buying and selling amount in the high level area. As soon as the amount of some commodity buying (or selling) in some region is quite great, and holds a greater proportion in high level area, the region can be regarded as main buying (or selling) base of this commodity. The distribution of buying and selling bases may be expressed by concentration index The factors which influence the buying and selling region distribution can be initially chosen with seating arrangement analysiis, and then the interrelated coefficient is used to find the main factor.2. The ratio of buying and selling theoretically reflects the relation of of commodity supplying and demanding of various regions.The location quotient of buying and selling reflects the situation of surplus and shortage of commodities. Buying and selling ratio can qualitatively decide the region of commodity transferring in and tansferring out, and the calculation of the amount of transferring in and transferring out can quantitatively decide the main regions of transferring in and transferring out of commodities. Under the known condition mentioned above, we can find the best trend of commodities throgh table work by linear programming.