Abstract: The semi-circular bending fracture tests of asphalt concrete were carried out, and the load-crack opening displacement curves during the crack propagation process were obtained. Combined with the steep drop method of linear correlation coefficient, the effects of temperature, loading rate, and initial crack length on the initial fracture toughness were studied. The digital image correlation method was used to study the damage and deformation characteristics of asphalt concrete during the crack initiation and propagation processes. Research findings show that the initial cracking load obtained by the steep drop method of linear correlation coefficient is within the ranges of experimental load when there presents damage, which verifies the reasonability of this method in studying the initial fracture toughness of asphalt concrete. The initial fracture toughness gradually decreases with the temperature and initial crack length and increases with the loading rate.