Hydrophobically associated poly (AM/AMPS/SMA) were prepared by free radical micellar copolymerization. The structure of the copolymer was characterized by FTIR. The influences of several factors on the apparent viscosity are studied, such as the initiation temperature, the amount of initiator, the monomer concentration, the hydrophobic monomer concentration, the surfactant concentration, and the monomer proportion. The results show that after incorporating anions and hydrophobic groups at the same time in the backbone of the polyacrylamide, the viscosity of the copolymer aqueous solution increases significantly under the coordination of the electric viscosity of anions and the hydrophobic association property of hydrophobic group. The hydrophobic associative behavior of the copolymer is studied by the fluorescence probe technique and, at the same time, the rheological properties of the copolymer aqueous solution are also investigated.