作为社会关系的重要一环，校友关系会对管理者决策产生影响。选取2012—2017年中国沪深两市A股上市公司为研究样本，利用固定效应模型检验董事长—总经理校友关系对公司创新投入的影响，通过考察公司内部控制和机构投资者持股对上述影响的调节作用，进而揭示其中相关作用机制。结果显示：董事长—总经理校友关系会促进公司创新投入；公司内部控制和机构投资者持股均正向调节董事长—总经理校友关系对公司创新投入的促进作用。进一步研究发现，董事长—总经理校友关系对公司创新投入的促进作用在非国有企业、高科技公司中更显著，而地区市场化程度差异对上述促进作用的影响并未表现出显著不同。研究结论能够为公司更有效地植入校友文化、完善选人用人与高管再教育机制等提供管理启示。

In the era of knowledge economy, the economic development model supported by traditional production factors has gradually got stuck in a development bottleneck, developing new knowledge and technologies is playing an increasingly important role in companies' lifetime. Companies obtain new knowledge and technologies by engaging in innovative activities such as developing unique products and services to ultimately gain a competitive advantage and increase market share, thereby promoting the improvement of operating performance. Although many literature papers conduct in-depth analysis of the company's innovation level, they are based on the economic man hypothesis, ignoring individual subjective factors. In fact, as a social person with emotions, reason, and social needs, managers are affected by various psychological factors.#br#On the one hand, the alumni relation is a social relationship based on academic relationships and has certain cultural specificities, because each university has its own unique culture and historical precipitation, on the other hand, school choice is a subjective choice and has the same educational background, alumni have similar cultural literacy and values, as well as rich professional knowledge. The alumni relationship can better meet the requirements of innovative activities, which is different from the fellow villager relationship and colleague relationship. In capital market, alumni relations have gradually condensed into various alumni circles, which have a huge impact on capital operations. At the same time, the chairman of corporation and the CEO are both the main body of corporate governance, and the social relationship between the two may affect the company's investment in innovation. In view of this, this paper studies the influence of the chairman-general manager alumni relation on the company's innovation investment in order to put forward valuable suggestions.#br#Taking the A-share listed companies in Shanghai and Shenzhen stock markets from 2012 to 2017 as samples, this paper uses the fixed effect model and selects possible factors from corporate finance, corporate governance and CEO personal characteristics as control variables to explore the impact of the chairman CEO alumni relationship on enterprise innovation investment. The results show that: #br#(1)Chairman-CEO alumni relation can significantly promote corporate innovation investment, means the social relationships of managers are playing increasingly important roles in the development of the company. They can restrain the behavior of the chairman and CEO through reputation and social capital, and play part of the corporate governance role. Under the current corporate governance framework, the principal-agent problem has become a constraint to the increase in the company's investment in innovation. If the chairman and general manager have an alumni relation, the above problems can be alleviated to a certain extent. #br#(2) Stronger internal control can significantly strengthen the positive impact between chairman-CEO alumni relation and corporate innovation investment, and more institutional investor shareholding can significantly strengthen the positive impact between chairman-CEO alumni relation and corporate innovation investment, which means companies can suppress the negative impact of the alumni relation by strengthening the company's internal governance mechanisms and improving the company's internal and external governance through market supervision.#br#(3)The positive impact between chairman-CEO alumni relation and corporate innovation investment will be different due to the heterogeneity of ownership and industry, which is stronger in non-state-owned enterprises and high-tech corporations, but the heterogeneity of regional marketization degree doesn't show a significant difference.#br#This paper takes chairman-CEO alumni relation and corporate innovation investment as the research objects, enriching the research on the relationship between this two aspects in particular field. Different from previous literature, this paper innovatively proves that informal relations and social capital have an important influence on individual decision-making, and extends relevant research. The empirical analysis supports the conclusion of the paper and strengthens the empirical research foundation of social capital theory. The research results also have instructive significance for the entrepreneurial activities. Corporations don't have to deliberately avoid this relationship when selecting managers, instead, corporations can use alumni status to enhance top managers' cultural identity and finally obtain more social resources. At the same time, corporations still need to establish and improve theirs' internal control system and improve the external supervision and restraint mechanisms to reduce the adverse effects of alumni relations.#br#