中文摘要：

价值链上下游企业之间存在大量的知识流,其中上行知识流（知识从下游向上游的流动）非常重要。本文系统地讨论并检验上游企业利用上行知识流促进自身创新的问题,具体地,我们分析了两种促进作用：立即作用,即运用下游知识马上就获得提升,这是一种直接的促进作用;延迟作用,即以往运用下游知识对以后创新的促进,这是一种通过培养上游能力而使其受益的间接促进作用。选取美国汽车生产行业中的零部件供应商为研究样本,基于专利数据构建计量指标开展实证检验,系统检验零部件供应商运用汽车生产商知识对其创新水平的促进作用,结果表明立即作用和延迟作用均显著,这一结果验证了汽车生产行业中价值链下游（生产商）是上游（零部件供应商）非常重要的知识源。

英文摘要：

There are plenty of knowledge flows among firms in a value chain,among which the upwards knowledge flow（that is,knowledge flow from the downstream to the upstream） is very important.We systematically studied the effect of upwards knowledge flow on the upstream＇s innovation.we respectively studied two types of effects： the simultaneous effect,that is,the when the upstream uses the downstream＇s knowledge he can be improved immediately;and the postponed effect,that is,the upstream previously uses the downstream＇s knowledge he can be improved later.Choosing the USA auto parts suppliers as our research sample and basing on patent data to construct our research variables,we test the effects.The test results show that either simultaneous or postponed effect works.This verifies that in the auto manufacturing industry,the downstream is important knowledge source for the upstream.