中文摘要：

在资金约束条件下,企业如何将资金在研究阶段与开发阶段进行结构配置是实务界和理论界亟待解决的重大问题。从理论上分析了资金约束下投资对研究阶段和开发阶段存在的结构差异,构建专利生产模型分析了融资约束下企业R＆D存在的投资结构选择,并进一步通过实证研究了现金流和研究阶段支出正相关与开发阶段支出呈反＂S＂型关系,以及和R＆D投资结构呈倒U型的关系。

英文摘要：

The discussion on how the firms allocate their R＆D capital to the research and development stages struc- turally under capital constraints has become a focus in practical and academic fields. We analyze the structural differences of investment between research and development stages under financial constraints. The optimal solution of patent production model indicates that the investment structure choices of R＆D varied with financial constraints. Empirical results demonstrate that cash flow has a positive correlation with research expenditure, while it show a reverse ‘S＇ curvilinear correlation with development expenditure. Even more interesting is that cash flow has an invert- ed-U relation with R＆D expenditure structure （R/D）. The study provides significant theoretical basis for the firms to make decisions on R/D investment Structure under different financial constraints.