在众多企业财务研究中，资本结构决策是企业管理者和管理层所面临的最基本的问题之一。公司财务是一个特定的领域的财务处理财务决策的公司和工具，以及分析用于作出这些决定。作为一个整体的纪律可能分为长期和短期的决定和技术的主要目标是最大限度地提高企业价值，同时管理公司的财务风险。资本投资决策是投资于股票或债务的长期选择，短期决策涉及流动资产和流动负债的平衡，管理现金、存货和短期借贷。企业融资可以被定义为理论，方法和技术，企业进行投资、融资和股利，最终有助于企业价值最大化的决策。因此，公司将首先决定哪些项目投资，然后找出如何资助他们，最后，它将决定多少钱，如果有的话，还给业主。投资、融资和股利分配这三个维度是相互联系、相互依赖的。
1. Introduction 简介
According to many research of corporation finance, the capital structure decision is one of the most fundamental issues facing to the executives and management level. The corporate finance is a specific area of finance dealing with the financial decisions corporations make and the tools as well as analysis used to make these decisions. The discipline as a whole may be divided among long-term and short-term decisions and techniques with the primary goal being maximizing corporate value while managing the firm's financial risks. Capital investment decisions are long-term choices that investment with equity or debt, and the short-term decisions deals with the balance of current assets and current liabilities which is managing cash, inventories, and short-term borrowing and lending. Corporate finance can be defined as the theory, process and techniques that corporations use to make the investing, financing and dividend decisions that ultimately contribute to maximizing corporate value.Thus, a corporation will first decide in which projects to invest, then it will figure out how to finance them, and finally, it will decide how much money, if any, to give back to the owners. All these three dimensions which are investing, financing and distributing dividends are interrelated and mutually dependent.The capital structure of a company refers to a combination of debt, preferred stock, and common stock of finance that it uses to fund its long-term financing. Equity and debt capital are the two major sources of long-term funds for a firm. The theory of capital structure is closely related to the firm’s cost of capital. As the enterprises to obtain funds need to pay some costs, the cost of capital in the investment activities is also the main consideration of rate of return. The weighted average cost of capital (WACC) is the expected rate of return on the market value of all of the firm’s securities. WACC depends on the mix of different securities in the capital structure; a change in the mix of different securities in the capital structure will cause a change in the WACC. Thus, there will be a mix of different securities in the capital structure at which WACC will be the least. The decision regarding the capital structure is based on the objective of achieving the maximization of shareholders wealth.
