中文摘要：

企业为使自己的利润最大，不仅需要制定正确的多代产品的价格，而且需要选好时机将新产品投入市场，这个时间的把握非常重要．通过Bass销售模型，建立了企业利润模型，对更新产品投放市场时机相关的因素做了数值分析，得到了一些性质，与实际情况比较吻合．

英文摘要：

To maximize the manufactures＇ profit, the manufactures not only need to make the pricing strategy of the generations of product, but also need to choose the optimal opportunity to introduce the renovations, and the second is very important. We present a profit model based on Bass diffusion model, analyze the relationship of optimal launch time with the parameters numerically. Some properties according with the reality are obtained.