Facing energy consumption and with consumer social responsibility increasing, the firms who produce traditional products consider whether to obsolete traditional products and introduce green productsthat are minimally harmful to the environment. Based on this, we establish a Stackelberg model and analyze three product-line strategies for the traditional product and the green product by considering the price and quality of the product(s). In all strategies, our study shows that the quality of the traditional product in a single-product line is the highest. For the wholesale and retail prices, the prices of the green product exceed that of the traditional product, and the prices of both products in the single-product line exceed those in the double-product line. Interestingly, the manufacturer prefers a double-product line strategy, but the retailer prefers to sell the traditional product. Moreover, only selling traditional products can provide a higher consumer surplus. Further, only producing green products generates the lowest environmental impact.