中文摘要：

以张伯伦的垄断竞争中“销售费用可以增加其所支持之产品的需要量；生产成本则会增加供给”的观点为基础，分析了销售费用对垄断竞争环境中市场均衡的产品数量、价格以及产品多样性的影响．文中的主要结论是和只考虑生产成本的情形相比，销售费用会降低产品多样性，但可以提高生产规模．

英文摘要：

The paper is based on the view of E. Chamberlin that sales expenditure can increase the quantity of products, and produet eost can increase supply. It investigates the effect of sales expenditure on equilibrium product quantity, product price and product diversity in the monopolistic competition market. The main con- clusion of the paper is that compared with the situation without sales cost, the cost can decrease product diversity and increase product scale.