This study explored the influence of power and power-rationality on the illusion of control by using experimental methods. We hypothesized that activation of the different behavior system will lead high-power individuals and low-power individuals have different experience in the sense of control: compared to low-power individuals, high-power individuals will have a greater sense of control, in other words, high-power individuals will have the illusion of control. Consider the conflicting behavior of high-power and low- power individuals when the power is legitimate and illegitimate, we believe that the legitimacy of power is also an important factor on the relationship between power and control illusion. Then we put forward a hypothesis: the legitimacy of power and power levels will have an interaction effect on the sense of control——when the power is legitimate, the high-power individuals will have significantly stronger sense of control than low-power individuals; when the power is illegitimate, there will have the opposite effect. In the current study, two experiments were designed to verify the above two assumptions. 87 undergraduates and 129 undergraduates and graduate students participated in the study. All these participants were recruited from the same school. During the study 1, participants are divided into two groups randomly. one of the two groups imagined themselves owning the power; the other imagined themselves being lack of power. Then both of them solved distribution shops problem. During the study 2, participants are divided into four groups randomly. Four groups are be made up of high legitimate power group, high illegitimate power group, low legitimate power group and low illegitimate power group. Then all of them solved distribution shops problem. Imagination of power the role and distribution role from false questionnaire score are used to manipulate the sense of power, distribution shops problem is used to measure the subjects' sense of control. The results show that these two assumptions are worked: a) the high-power will lead to overestimation of the illusion of control（F（1,85）=4.237，p=.043）; b）while power relationship is legitimate, high power lead to overestimation of the illusion of control; while power relationship is illegitimate, low power rather than high power lead to overestimation of the illusion of control.（ F （1，124）=10.552，p=.001）. This study provides empirical support for the power approach / inhibition theory and reveals the illusion of control can be determined by the dynamic of power relations based on the context and power-rationality. The study also shows how power, once attained, is maintained （as well as how it is lost），and so on.