Because of the concentration effect, the kinematic viscosities of the CNF solutions increased with the CNF concentration. However, adding the NaCl neutralized the electric charges of the chitin molecular chains, prompting the CNFs to gather and form gels. At a CNF concentration of 0.075 g/L, the gel strength was weak because of the low CNF concentration. The gels were thus easily broken apart and became dispersed and fluid-like when stirred mechanically, which lowered their kinematic viscosity. At CNF concentrations of 0.15 and 0.30 g/L, the gel strengths were strong because of the high CNF concentrations. Although the gels were still broken apart and became dispersed and fluid-like when stirred mechanically, they formed tiny particles and displayed poorer fluidity, which increased their kinematic viscosities.