Abstract: After sorting out a large number of literatures. It is found that: 1) in theory, most of the literatures discuss the intrinsic mechanism of controlling shareholder's expropriation and how to strengthen corporate governance to restrain it. Also,there still many researchers examine the impact of the opportunistic behavior of the controlling shareholder on investment and financing decisions.For instance, Morellec and Wang (2004) have begun the task of incorporating imperfect investor protection into the real options model and examine the impact of opportunistic behavior by the insider of the company on corporate investment decisions. 2) however, researchers all follow the hypothesis of coincidence of individual time preference in frame of the neoclassical financial theory and ignore the most significant factor ---time-inconsistent Preferences---which can match the reality very well since the individual's preferences for future periods are completely different. Furthermore, the decision makers’ time preference inconsistency has a significant impact on enterprise decision-making. If simply the consistency preference were assumed, it is dangerous for it is probably to get a wrong conclusion concerning when will invest and what the optimal scale of investment for company or controlling shareholders. Therefore, in order to be more in line with the reality, this research is on the basis of 1) and 2) to explore the intrinsic mechanism of control shareholder's expropriation to corporate decision-making under the premise of inconsistent preference.In this research, based on a continuous-time model of quasi-hyperbolic discounting, an analytically tractable model is provided in which the controlling shareholder can divert part of the firm’s cash flow as private benefits at the expense of outside shareholders. The theory assumes that controlling shareholder maximizes the present value of his future cash flow, subject to constraints imposed by outside shareholders property rights to the firm’s assets. The value of the controlling shareholder and is given the algebraic equations of the investment threshold, investment quantity and abandon level are given by the method of dynamic programming and equilibrium pricing. It is found that the control shareholders having time-inconsistent preferences will not hold all equity, the optimal equity ratio is between 20% and 30% in most cases, and mature control shareholders hold lower optimal equity ratios than naive control shareholders. Compared with the optimal case without agency conflict, controlling shareholders with time-inconsistent preferences show delayed investment, but the scale of investment increases first and then decreases as the degree of inconsistency increases. At last, the analysis of optimal equity holding by the controlling shareholder and investor protection parameter show that consideration of time-inconsistent preferences of controlling shareholders can produce a fresh perspective for corporate governance. The distorted behavior mechanism of controlling shareholders and the optimal share structure ratio under time-inconsistent preference are of great significance to analyze the influence of investor protection on controlling shareholders' investment decision-making, and provide help for corporate governance.

Key words: time inconsistent preference, private interest over control, investment strategy, optimal equity structure