文章以《关于2018年退还部分行业增值税留抵税额有关税收政策的通知》政策出台为准自然实验，选取2015—2020年沪深A股上市公司为研究样本，采用双重差分模型研究了“留抵退税”政策的实施对企业研发创新的影响。研究发现：与对照组企业相比，“留抵退税”政策的实施显著增加了实验组企业的创新水平；从企业生命周期角度进行异质性分析发现，“留抵退税”政策对成长期、成熟期企业的创新水平都具有显著的促进作用，而对衰退期企业的创新水平并没有显著影响，相较于成长期企业而言，该政策更能提高成熟期企业的创新水平；在区分产品市场竞争程度的情况下发现，“留抵退税”政策对低产品市场竞争程度企业的创新水平促进效果显著。研究印证了“留抵退税”政策对企业创新的促进作用，为新一轮的增值税改革提供了重要的政策启示。

The study takes the implementation of "Notice on Tax Policies Concerning the Refund of Value-Added Tax Credits for Certain Industries in 2018" as a quasi-natural experiment, selects Shanghai and Shenzhen A-share listed companies in 2015—2020 as the research samples, and uses the DID model to study the effect of the implementation of this policy on enterprise innovation. It is found that compared with the enterprises in the control group, the implementation of the "VAT rebate" policy significantly increased the innovation level of the enterprises in the experimental group. The policy has a significant promoting effect on the innovation level of enterprises in the growth or maturity period, but has no significant impact on enterprises in the recession period. Compared with enterprises in the growth period, this policy can better improve the innovation level of enterprises in the maturity period. In the case of market competition, it is found that the "VAT rebate" policy has a significant effect on promoting the innovation level of enterprises with low product market competition. The research confirms the promotion effect of the "VAT rebate" policy on enterprise innovation, and provides insights for the new round of value-added tax reform.