The debate about the function of base-rate in Bayesian reasoning has never been stopped. There are three main viewpoints: (1) people overweight the base-rate; (2) people neglect the base-rate completely; (3) people take it into account, but think poorly of its function. Considering the majority existing studies use the posterior probability and reaction time to infer the reasoning process reversely and lack support of the real-time data, the study provided eye-movement evidences for the process of Bayesian reasoning by using Eye View Monitoring Systems for the first time. The research hypothesized that the eye-movement targets induced by different levels of base-rate and cognitive styles will be significantly different. Thirty-five college students were sampled for this experiment. In order to examine the effects of two different levels of base-rate (e.g. high vs. low) and two kinds of cognitive styles (e.g. the field dependence cognitive style vs. the field independence cognitive style) on Bayesian reasoning , the study recorded the total fixation duration and numbers of fixation by using Eye View Monitoring Systems. The inference materials were about illness which were divided into four area of interests (AOI), AOI1 was about the base-rate, AOI2 was about the hit-rate, AOI3 was about the false alarm rate, and AOI4 was the area where the question located. The results were as follows: (1) when compared the total fixation duration and numbers of fixation, the main effect of base-rate and cognitive style were not significant, but the interaction between them was significant, and the simple effect analysis showed: a. when the base-rate was low, the total fixation duration and numbers of fixation of the group with the field dependence cognitive style were more than those of the group with the field independence cognitive style; b. the total fixation duration and numbers of fixation of the group with the field independence cognitive style in high base-rate level were more than those in low base-rate level; (2) when compared the total fixation duration and numbers of fixation, the main effect of AOI was significant, the order of the extent of each AOI was paid attention to was: AOI2＞AOI3＞AOI1＞AOI4. These results indicated that: (1) in the process of Bayesian reasoning, the probability information were differently followed with interest, the order was: hit-rate＞false alarm rate＞base-rate, and the base-rate was not neglected completely but was just underweighted. (2) people with different cognitive styles held different process ways, generally speaking, people with the field independence cognitive style intended to think rationally while those with the field dependence cognitive style were always influenced by the external information.