Based on the structure and function of antifreeze protein, poly ( aspartic acid ) grafted from ethanol amine was synthesized and used as biomimetic cryoprotective agent. The structure was characterized by Fourier transform infrared spectroscopy ( FT?IR ) and nuclear magnetic resonance hydrogen spectrum 1H NMR. The antifreeze performance and morphology of ice crystal were determined by differential scanning calorimetry ( DSC) and optical microscopy. Results showed that these polymers interfered with the crystallization process of water. The differential scanning calorimetry results showed that polymers with higher grafting ratio had better thermal hysteresis activity and decreased the freezing point. Meanwhile,the ice crystal showed the smaller and rounded particle morphology. It was exhibited that the grafting rate at 80% had the highest thermal hysteresis activity ( 0?44℃) and the cryoprotective agent concentration threshold was 5 mg/mL. Results demonstrated that the synthetic biomimetic polymer could be used as a cryoprotective agent.