In view of the seasonal products

this paper designs a two-echelon supply chain network

which who has multiple suppliers and retailers

and each supplier has a corresponding warehouse and inventory is restricted. The locations of the supplier and the retailer are known

and retailer has corresponding discount when purchases different products from suppliers weset the distance of the retailers and suppliers to Euclidean distance. By search- ing the optimal supplier

we minimize the total inventory cost including transportation cost

inventory holding cost and purchasing cost. The example is solved by MPSO and GA respectively. Finally

comparison and analyzing the