OBJECTIVE  To investigate the effect of different proportions of researchers in the research and experimental development(R&D) workforce of pharmaceutical manufacturing industry on the relationship between R&D investment and innovation performance.

METHODS  Inter-provincial panel data of pharmaceutical manufacturing industry in China from 2011—2017 were used as samples, and a panel threshold regression model was established with the proportion of researchers as the threshold variable to explore whether there was a threshold effect in the relationship between R&D investment and innovation performance.

RESULTS  When the proportion of researchers was used as the threshold variable, there was a significant threshold effect between R&D investment and both innovation performance of patent applications and new product sales income in pharmaceutical manufacturing industry. As the proportion of researchers increased, the contribution of R&D investment to patent applications decreases, and the contribution to new product sales income tends to increase and then decrease. When the proportion of researchers in the R&D manpower team was >35.182% and ≤38.950%, R&D investment could achieve the optimal output effect on both innovation performance.

CONCLUSION  The innovation efficiency of R&D team is higher when the proportion of researchers in R&D manpower team of pharmaceutical manufacturing industry is controlled at >35.182% and ≤38.950%, and the promotion effect of R&D investment on innovation performance is more significant.