Supply chain ordering model with delivery delay based on buy-back contract is established. The impact of
delivery delay rate on the order quantity of supplier and retailer is analyzed as well as the profit. It is shown that the coordination buy-back price in delivery delay is less than that in non-delivery-delay. The supplier prefers high buy-back price and low delivery delay penalty and the retailer prefers low buy-back price and high delivery delay penalty. Both of them are willing to share more demand risk and less delivery delay risk. Example analysis verifies the above conclusion.