Abstract Based on the IBV(Institution-Based View of Business Strategy), this study investigates the impact of NIS(National Innovation System) on R&D with a pooled data sample of the 8 312 main board and SMEB companies for the period 2003~2013. The result showed that there was a significantly positive relationship between the NIS and the next-year R&D input of main board and SMEB companies, and then the leverage and firm age was the moderator of the relationship between NIS and the R&D input of main board and SMEB companies, but the moderating effect was different. Specifically, the leverage could reduce the incentive effect of NIS on the firm R&D input. The firm age could improve the incentive effect of NIS on the firm R&D input.