Abstract: To improve the water stability of asphalt pavement under the condition of salty and humid environment in coastal areas, the feasibility of applying indirect tensile strength to asphalt mixture design was analyzed first. Then, the indirect tensile tests under different conditions were carried out, and the influences of test temperature, loading rate and asphalt content on ITS were analyzed. Finally, the correlative analysis of ITS under different conditions and results of freeze-thaw splitting test was carried out. The results show that ITS of asphalt mixture decreases with the increasing of test temperature and increases with the increasing of loading rate. ITS increases with increasing of asphalt content at first and then decreases, and ITS gets its peak at certain asphalt content. Under the temperature of 40℃ and loading rate of 5mm/min, the correlation of ITS and TSR is the highest. The ITS under that condition can be regarded as a mechanical parameter for optimum asphalt content design of asphalt mixture in coastal areas.