Taking vehicle type analysis as a startpoint， it studies the car styling with both qualitative and quantitative research approach to probe semantic-driven design method. By constructing the vehicle type model of prototype category， by means of analysis， induction，deduction， the relationship between type members and prototype similarity degree， type members contribution， weight coefficients of the prototype category can be formalized. Taking SUV as an example， 14 groups of contour fitting model are obtained， and 11 groups of core differential semantic vocabulary of SUV are used to generate SUV contour. Using prototype category to analyze vehicle type provides more objective， reasonable and flexible guide to car styling， which is a way closer to the cognitive rules and thinking model to car designer.