The paper is devoted to the comparison of one-dimensional models, used for the simulation of blood flow in elastic vessels. The inviscid, Newtonian, and non-Newtonian models of blood are considered. The one-dimensional non-Newtonian models, corresponding to widely-used rheological models with shear-dependent viscosity (Power Law, Carreau, Carreau–Yasuda, Cross, simplified Cross, modified Cross, Powell–Eyring, modified Powell–Eyring, Yeleswarapu, modified Yeleswarapu, and Quemada) are presented. The attention is focused on the investigation of the influence of viscosity, shape factor, velocity profile, non-Newtonian viscosity, and hematocrit. In the numerical experiments, the models of arterial systems with twenty and thirty-seven vessels are considered. It is demonstrated, that for the vessels near the heart the effect of viscosity can be considered as inessential, and an inviscid model can be used. The main effect on the relative deviations of solutions, obtained by different models, is realized by the velocity profile. The effect of non-Newtonian viscosity is not so essential, but can be taken into account for the models with peripheral vessels.