Abstract: To study multi-stage optimal ordering strategies for the manufacturer under uncertain prices, a stochastic netcash flowmodelwas proposed in view of themanufacturer. In themode,l it is assumed that the supply chain is composed of a single manufacturer and a single supplier from any country in theworld, their contract is quantity-flexible, exchange rate changes as geometric Brownian motion, and out-of-stock is allowable by themanufacturer. The optimal strategies can be obtained by solve the model with binomial lattice method. The efficiency for solving the model is positively dependenton the number ofordering and the size of the feasible solution setof every ordering period. The feasibility of themodel and the algorithm for solving itwere verifiedwith an example.