A functional monomer (DAMA) was prepared with 1,3-Diaminopropane and maleic anhydride, and then a water-soluble AM-AA-NVP-DAMA tetra-copolymer was polymerized by free radical polymerization using DAMA, N-Vinyl-2-pyrrolidone (NVP), acrylamide (AM), and acrylic acid (AA) as raw materials. The synthesis conditions were as follows: m (AM): m (MA) was 3:2, initiator was 0.5 wt%, temperature was 40 oC, reaction time was 8 h, and pH was 7.0. The AM-AA-NVP-DAMA copolymer was characterized by infrared spectroscopy (IR), 1H NMR, and scanning electron microscope (SEM). It was found that the viscosity retention rate of AM-AA-NVP-DAMA was 16.2 % higher than that of partially hydrolyzed polyacrylamide (HPAM) at 95 oC, the viscosity retention rate of this copolymer in 1.8 wt% NaCl brine was 8.7 % higher than that of HPAM, the viscosity retention rate of this copolymer in 0.09 wt% CaCl2 brine was 9.4 % higher than that of HPAM, and the viscosity retention rate of this copolymer sheared at 500s-1 for 5 min was 16.3 % higher than that of HPAM. It was also found that the enhanced oil recovery (EOR) of 0.2 wt% copolymer solutions was 5.07 % higher than that of HPAM at 60 oC.