Abstract: R&D investment is the key to change economic development pattern and enhance the industrial competitiveness. In recent years, with the increasing R&D espenses in China, whether the more R&D investments are the better has become a much-debted issue. This article uses the panel datas of 36 chinese industies from 2002 to 2009 as samples and applies the threshold regression model to test the influence of R&D investments to the performance of thoes industies. According to the empirical results on the basis of all industrial sectors, 0.0089 is the single threshold value of R&D strength. Moreover, it is demostrated that the action mechanism of R&D investments is obviously different in those industries with diverse qualities. Specifically, the threshold effects in the industries of mechanical and electronic and resources processing are relatively more remarkable, and the threshold values(0.0125&0.0020) reflect the characteristics of factor intensity; In addition,there is no threshold effect in the taxtile manufacturing because of its lower R&D strength.

摘要： R&D投资是转变经济发展方式和增强产业竞争力的关键，近年来随着我国研发经费支出的持续增加，作为要素投入的R&D投资是否越多越好成为亟待讨论的重要问题。本文以中国36个工业行业2002-2009年的面板数据为样本，利用门限回归模型检验了R&D投资对行业绩效的影响，来自全部工业行业数据的实证结果显示，R&D强度存在唯一的门限0.0089。分大类行业的估计结果表明：研发投资的作用机制在不同属性行业中存在明显差异，机械电子和资源加工业的R&D投资门限效应较为显著，且门限值（0.0125,0.0020）反映了行业生产的要素密集度特征；轻纺制造业由于R&D强度处于较低水平，不存在门限效应。

关键词: R&D投资, 门限效应, 工业部门, R&D investment, threshold effect, industrial department