Abstract:     The characteristics of managers are an important factor affecting the R&D investment of enterprises. Managers′ personality characteristics, work experience, industry cognition and insight, and relevant professional and technical knowledge all affect the direction and strength of research and development. Firstly, based on the theoretical analysis of the relationship between manager characteristics and enterprise performance, this paper proposes the hypothesis of the correlation between manager characteristics, R&D investment and enterprise performance. The hypotheses are as follows: there is a positive correlation between the biographical human capital characteristics of enterprise managers and enterprise performance; the non-biographical human capital characteristics of enterprise managers are negatively correlated with enterprise performance. The non-biographical human capital characteristics of enterprise managers are negatively correlated with enterprise innovation R&D investment. Innovation R&D input is the intermediary variable between human capital characteristics of enterprise managers and enterprise performance. There is an intermediary effect between the characteristics of enterprise managers, innovative R&D investment and enterprise performance.The objectives and methods of this paper are as follows: The main objectives of this paper are the relationship between the characteristics of enterprise managers, innovation R&D investment and enterprise performance，and the mediating effect of innovative R&D investment between enterprise managers′ characteristics and enterprise performance. In terms of research methods, this paper takes the innovation R&D input of enterprises as the intermediary variable to construct the influence path between the human capital characteristics of enterprise managers and enterprise performance, and explore the internal mechanism between the characteristics of enterprise managers and enterprise performance. By using the empirical research method, this paper describes the human capital of enterprise managers from the four dimensions: age, education, tenure and professional title, and studies the relationship between the characteristics of human capital of enterprise managers, innovative R&D investment and enterprise performance from the two perspectives of biographical and non-biographical, so as to explore the mediating effect of enterprise innovative R&D investment. In this paper, the explained variable is enterprise performance, and the explanatory variable is the characteristics of enterprise managers. Innovation R&D investment is taken as an intermediary variable, and finally several control variables are added. By controlling other main variables that affect enterprise performance, the results of calculating the influence of enterprise managers′ characteristics on enterprise performance are more accurate.The main conclusions of the study are as follows: There is a positive correlation between the education level of enterprise managers and enterprise performance, and the improvement of education level is conducive to the improvement of enterprise performance; The tenure of enterprise managers has a negative impact on enterprise performance, the longer the overall term of office is, the worse the economic profit of enterprises will be. The title of enterprise manager is negatively correlated with enterprise performance, the higher the degree of professional title, the worse the growth of enterprise performance. The relationship between the age of enterprise managers and enterprise performance did not pass the significance test, most managers are experienced in management, age does not have a significant impact on corporate performance. The age heterogeneity of enterprise managers is positively correlated with enterprise performance, the greater the age heterogeneity, the more conducive to improving enterprise performance; The heterogeneity of tenure has a positive effect on enterprise performance, the greater the heterogeneity of tenure, the better the economic profit. The relationship between the heterogeneity of educational level and professional title of enterprise managers and enterprise performance did not pass the significance test, the educational level of managers is closely related to their professional titles. They do not have a great impact on managers′ management experience, and thus do not have a great impact on enterprise performance. The human capital characteristics of enterprise managers will play a role in innovation R&D investment. The professional title of enterprise managers is positively correlated with the R&D investment of enterprise innovation, the higher the professional title, the more emphasis on R&D investment; The education level of enterprise managers is positively correlated with innovation R&D investment, higher education level will increase R&D input; The tenure of enterprise managers has a positive impact on enterprise innovation R&D investment. The longer the tenure, the more willing to increase the R&D investment. The significance test between the age of enterprise managers and the R&D investment of enterprises did not pass, indicating that managers do not ignore the importance of innovation because of their age. The age heterogeneity of enterprise managers is negatively correlated with the R&D investment of enterprise innovation. The higher the age heterogeneity is, the lower the R&D investment will be. The heterogeneity of managers′ tenure has a negative impact on enterprises′ innovative R&D investment, the greater the difference in tenure, the worse the increase in R&D investment; The heterogeneity of managers′ education level is unrelated to R&D investment, and the difference between managers′ education level does not affect their attitude towards R&D investment. The relationship between title heterogeneity of enterprise managers and innovative R&D investment has not passed the significance test. Like the heterogeneity of education level, the heterogeneity of title does not affect the importance of innovative R&D in enterprises. Innovation R&D investment plays an intermediary role in the relationship between title, education level, tenure and enterprise performance in the characteristics of corporate managers′ biographical human capital. There is no intermediary effect between the age of enterprise managers and enterprise performance, and the age of managers will not affect the R&D investment of enterprises and thus affect enterprise performance. Innovative R&D investment plays an intermediary role in the relationship between age heterogeneity, tenure heterogeneity and enterprise performance in the non-biographical human capital characteristics of enterprise managers. There is no mediating effect between the heterogeneity of managerial title, educational level and enterprise performance. 

Key words: manager characteristics, R&D input, enterprise performance, mediating effect