Static creep tests were conducted on three kinds of asphalt mixtures under different temperatures and stress levels. The property of creep deformation was analyzed. The mechanical parameter k(creep rate, that is, the second phase slope) was obtained according to the stress strain relations. The effects of temperature and stress on creep rate of asphalt mixture were discussed. Form the relation of creep rate with temperature stress, stress exponent and creep activation energy were calculated to analyze the creep mechanism of asphalt mixture. The results show that k increases gradually with temperature and almost linearly with increasing load stress. The stress exponents of three mixtures have no significant difference, and they are all diffusion creep controlled by the mechanism of mineral aggregate interface. The creep activation energy has close relation with dynamic stability, which reflects high temperature performance of asphalt mixture.