Asphalt pavement performance in seasonal frozen region is affected severely by the freeze-thaw cycles. Gradation has important effects on asphalt mixture's freeze-thaw durability. This paper presented the standard test methods of freeze-thaw cycles and analyzed the freeze-thaw durability of asphalt mixtures with different gradation. The test results showed that the freeze-thaw damage of asphalt mixtures goes through three stages. With the increase of freeze-thaw cycles, the splitting strength of mixtures decreased and the volume expanded gradually. The performance stabilized until the next rapid deterioration caused by the loss of interfacial adhesion between the asphalt and aggregate. The results also indicated that the mixtures with dense gradation had the best freeze-thaw stability than others, and the semi-open graded mixtures performed worst. The study results can be used in technical guideline for freeze-thaw durability of asphalt mixtures in seasonal frozen region.