Microstructure and formation process of the material mixed with anticracking agents were observed by the scanning electronic microscope. It is found that the anticracking agent has expansion character and can make the material dense. Through the shrinkage tests, it is proved that the shrink spaces of the road base, which is caused by the variations of the temperature and humidness, decrease apparently because of the anticracking agent. The influence of delaying the molding time on the strength of gravel mixtures is also analyzed and it is concluded that anticracking agent has slow setting performance. On account of adding anticracking agent into the semirigid base material, early strength of the material is enhanced, curing period is shorten and lasting quality is improved, which can be showed from the durability test. The continuous constructions of the base and asphalt pavement are feasible in the test road because of anticracking agent, which make the base and surface pavements compacted tightening. Thus, cracking of the pavements can be restrained, durability of the road can be improved and road life can be extended.