In this paper, we develop an analytical model to study if managers’investment decisions would differ between various accounting methods for convertible bonds. We also try to investigate the factors that would affect the difference. The result shows that, the difference might exist when managers are risk averse. Besides, other factors such as gains or losses on bond conversion, the intensity of incentives for the managers, managers' initial wealth, and risk and return of the projects also affect the decisions, and there are also interdependences among these factors.