The water-soluble zwitterionic copolymer (ANND) was synthesized by acrylamide (AM), acrylic acid (AA), N-(3-methacrylamidopropyl)-N,N-dimethylheptadecan-1-aminium bromide (NADA) and phosphate group-containing monomer 1-dimethylaminoallyl phosphoric acid (DMAAPA). And then, the copolymer was characterized by IR, and the properties (salt tolerance, temperature resistant, rheology etc.) of it were studied. The results showed that the apparent viscosity of 2000 mg/L copolymer solution was 40.48 mPa·s at 100 ℃ and shear rates of 170 s-1, and 28.46 mPa·s at 500 s-1 in 25 ℃. Furthermore, to study the aging properties of copolymer, it has been kept in water bath at 80 ℃ for 10 days. The result illustrated that the viscosity retention rate of copolymer could remain 38% which is higher than 17% of HPAM. And it could remain 28.9 mPa·s, 32.1 mPa·s, 30.7 mPa·s in 30000 mg/L NaCl, 2000 mg/L CaCl2 and 2000 mg/L MgCl2 solutions, respectively. While the HPAM only 9.8, 17.7 and 16.3 mPa·s remains at same conditions. The stimulating displacement experiment indicated that the recovery ratio of 2000 mg/L copolymer solution was enhanced 14.3%.