Requirements: the goods at the lowest cost of transportation from point A (A1, A2, A3... ) transportation to the point of demand (B1, B2, B3... ), meet the demand of the goods, the data: different space position of supply and demand, different grade road map, unit price, etc., note: different supply points and demand points has its certain supply and demand, different speed, different road grade transporter limited volume, the demand of the different point has the highest purchase costs would have limited (purchase cost is equal to the delivery from the supply point of demand point the transport costs),