Ethylene - vinyl acetate copolymer (EVA)-modified mortar is widely used in China because of better adhesion strength and flexibility as compared to traditional one. This paper, based on a laboratory program, evaluated the effects of EVA-cement and different fillers on interface properties of EVA-modified cement mortar such as adhesive strength and dynamic cracking resistance, and the mechanism was also analyzed by scanning electron microscopy (SEM). The results showed that under laboratory condition, adhesion strength and dynamic cracking resistance of EVA-modified cement mortar increased with EVA-cement rising. Interface performance of the EVA-modified mortar improved greatly as EVA-cement increased from 0% to 12% and amplification slowed down when it increased further. EVA-cement around 12% was the optimal proportion considering all factors in this study. Fillers of different particle grade contributed to interface properties of EVA-modified cement mortar, A/fillers around 1/6~2/3 is the optimal proportion in this study.