Refurbished products, due to their lifecycle, have the least harmful effects on the environment, but the consumer willingness to buy these products is low. To promote the use of refuerbished products, different tools such as appropriate pricing and product warranty can be used. This thesis investigates the pricing decisions and determines the warranty period for new and refurbished products. The focus of this study is on a closed-loop supply chain with a manufacturer and a collector that offers new, refurbished, and recycled products. The manufacturer manufactures new-brand product and refurbishes returned items, while the collector purchases used product from the consumer and sells it to the manufacturer or will be recycled and will be sold in a second market. In the first issue the consumer's preferences over the refurbished product and the new product is not considered, while in the second issue it is assumed that the consumer has a different preference for purchasing of a new product than the refurbished product. In fact, if two types of products have the same price, consumers would prefer to buy a new product. In this study, for the first time, it is assumed that the difference in the warranty period of these two products affects on the customer's preference for the purchase of the product. After solving the problem by game theory, the optimal product prices and the optimal warranty periodes for both products are determined. The purchase price of the returned product from the consumer and the amount of collector's effort to collect the used products are also determined. Finally, parametric analysis and numerical examples are provided
