This paper argues why Hayek is not a conservative from four aspects. It starts by laying out three important debates between libertarianism and traditional conservatism in the 1950 s and by clarifying the intellectual background and motivation of Hayek’s writing "Why I Am Not a Conservative. "It then introduces three types of conservatism—aristocratic,autonomous,and situational—put forward by Samuel Huntington.The paper argues that Hayek rejects the aristocratic definition of conservatism when he criticizes its traditionalistic,anti-intellectual,and often mystical propensities,and that Hayek also rejects situational conservatism,criticizing it as being closer to socialism than true liberalism due to its lack of political principles. Although there are many overlapping ideas between Hayek’s thought and the autonomous definition of conservatism,they are inadequate for labeling Hayek as a conservative.