Management strategy and governance can affect a company’s investmentefficiency. If a company makes strategic decisions well, the company’sreturn on investment will increase, and investment efficiency can beimproved. On the other hand, if a company makes irrational decisions orif management acts in conflict with shareholder interests, the company’sreturn on investment will decrease, and investment efficiency will alsodecline. Therefore, companies need to understand the relationshipbetween their management strategy and governance and investmentefficiency and take appropriate measures.In this paper, I analyzed the impact of governance and managementstrategy on a company’s investment decision-making, focusing on leadingmanagement strategy companies. We expected that the investmentefficiency of leading management strategy companies would improve asgovernance improved. The analysis showed that the better the firstgovernance structure, the better the investment efficiency. Even if it is aleading management strategy group, if the governance structure is notgood, the investment inefficiency is lower than when the governancestructure is good. In cases where the governance structure is good,excessive investment by leading management strategy companiesdecreases, and underinvestment by defensive management strategycompanies has little effect, and there is not much difference betweengroups. Second, in cases where the governance structure is not good,excessive investment by leading management strategy companies increases,and underinvestment by defensive management strategycompanies also increases, so the effect is further enhanced in groupswhere the governance structure is not good.The contribution and implication of this paper is that it verified therelationship between governance and management strategy and acompany’s investment efficiency for the first capital market participants.Second, it systematically proved that even if it is a leading managementstrategy group, if the governance structure is strengthened, appropriateinvestment management is carried out, and investment efficiency isimproved, thereby confirming the importance of governance again. Inaddition, it presented logical evidence that investment efficiency can beimproved through good governance, which is as important as corporatemanagement.