中文摘要：

在Hotelling模型的基础上，对具有网络外部性特征和存在R＆D溢出条件下厂商的R＆D决策和创新动机进行了理论研究．研究结果表明：网络外部性越强或需求方的学习成本越低，厂商的R＆D投资越多．当厂商具有较低（较高）的R＆D投资效率时。较强的网络外部性会削弱（增进）其R＆D动机，而较高程度的兼容性和较高的需求方学习成本会增进（削弱）其R＆D动机．

英文摘要：

This paper theoretically studies firm＇s incentives within the Hotelling model. The conclusion shows that when network externalities are stronger or the learning cost of demand side is lower, the firm will invest more . When the finn＇s efficiency is lower （higher）, the stronger network externalities will make its incentive to innovation weaker （stronger）, and the higher compatibility and the higher learning cost of demand side will make its incentive to innovation stronger （weaker）.