The aqueous solution properties of an ampholytic poly(3-dimethylacryloyloxyethyl ammonium propiolactone), poly(DMAEAPL), are examined in this study by measuring reduced viscosity, intrinsic viscosity, degree of binding and dynamic light scattering. This polyampholyte’s intrinsic viscosity is related to the type and concentration of the salt added. The intrinsic viscosity behaviour for the polyampholyte resulting from the associations of the polymer chains is in contrast with cationic and anionic polyelectrolyte. The polyampholyte in high concentration of NaCl has a low degree of binding, indicating that the proton ion (H+) has difficulty in binding to the carboxylate group (COO-) at the polymer end. The carboxybetaine, DMAEAPL, has a higher degree of binding than the corresponding sulfobetaine, DMAPS. Dynamic light scattering measurements indicate that the poly(carboxybetaine) diffusion coefficients decrease and the chain dimensions increase with an increasing salt concentration. The models proposed in this study can account for the poly(DMAEAPL) solution viscometrics and the degree of binding.