Abstract: 37 kinds of graphs wereselected onthetheory of integrating design and practical application. The graphs were divided into elementary type, special type and extended type. The method included using subjective questionnaire and static experimental,recording the visual cognition time of different graphs and combining with the method of one-way ANOVA. The result indicates that the visual cognition time of the 37 graphics presents substantial difference. From the classification point of view, graphs of special type and extended type indicating complex interchange are more difficult to visual cognition than those of elementary type indicating standard single interchange. The visual cognition time is 1.18times. In diagrams of elementary type, the diagrams for loop ramps are more difficult to visual cognition than those for directional ramps and semi-directional ramps. The visual cognition time is 1.31times. The form of arranging the exit of right-turn ramp ahead of the exit of left-turn ramp is more conformity to the thinking habit of drivers and the visual cognition time is shorter.