The effects of NaCl on the rheological properties of collagen solutions were studied by steady shear test and thixotropic loop test. The results showed the rheological properties of the collagen solutions with different NaCl concentrations were quite different. With low NaCl concentrations (0 to 0.1 mol/L), the collagen solutions exhibited salting in effect. The pseudoplastic behavior of the solutions became weak, while the thixotropy became strong. The collagen solutions with high NaCl concentrations (0.1 to 0.3 mol/L) exhibited salting out effect. The pseudoplastic behavior of the solutions became strong and the thixotropy had no obvious variation. In addition, Ostwald de-waele model, Carreau model and Herschel-Bulkley model were used to fit the experimental data. The superimposed experimental data and the model curves indicated the suitability of the models used, except for the up curves in thixotropic loop test.