Abstract: Raising the Innovative Efficiency of the National Research Institutes(IENRI) is very important for increasing independent innovative capability and building an innovative-type nation.The evaluation of the IENRI can provide the policy support for the improvement of the IENRI.An evaluation model and measuring method of the IENRI is put forward.The evaluation model includes the concept models of the innovation output,the innovation input,and the innovative efficiency.The latter consists of innovation output per capital,and innovation output per unit of budget.The measuring method includes the accounting of the innovation output,the innovation input,and the innovative efficiency.The evaluation and statistical analysis of the innovative efficiency of the 19 national research institutes during the past 9 years in China is described,and some discoveies has made.There is the "diminishing returns of the innovation output per unit of budget".When the research budget per capital increases and exceeds a critical value,the innovation output per unit of budget will decrease.The evaluation model and measuring method of the IENRI are efficacious and are restricted in a certain extent.

Key words: national research institutes, innovative efficiency, evaluation models, diminishing return