To study the influence of polyampholyte’s molecular structure on its rheology, the copolymers of acrylamide (AM) and diallyl dimethyl ammonium chloride (DMDAAC) were synthesized via free radical copolymerization, and then were hydrolyzed with NaOH to produce nine polyampholyte-hydrolyzed poly(AM/DMDAAC) (abbreviated by HPAD-1, HPAD-2, HPAD-3, HPAD-4, HPAD-5, HPAD-6, HPAD-7, HPAD-8 and HPAD-9) with varied intrinsic viscosity, anionicity and cationicity. These polymers were characterized by IR, 1H NMR, titration and Ubbelohde capillary viscometer. The apparent viscosity and shear thinning behavior of HPAD solution were studied by using rotational viscometer and rheometer, respectively. The results revealed that HPAD’s intrinsic viscosity was in a positive correlation with both its solution viscosity and shear thinning effect. The apparent viscosity of 0.75% HPAD solution (mass fraction) increased from 12.1 mPa•s (HPAD-9) to 766.5 mPa•s (HPAD-7) when the intrinsic viscosity grew from 182.03 mL/g to 555.08 mL/g. The anionicity and cationicity of HPAD were negatively correlated with solution viscosity, and had little influence on shear thinning behavior. The apparent viscosity of 0.2% HPAD solution (mass fraction) decreased from 111.1 mPa•s (HPAD-1) to 21.5 mPa•s (HPAD-4) when the anionicity enhanced from 29.98 mol% to 51.75 mol%. HPAD-2 and HPAD-8 with cationicity of 10.31 mol% and 6.88 mol% respectively, had almost coincided shear thinning curves in the range of 5 s-1 to 100 s-1.