In this study, a new method is presented to correlate the shear viscosity of nanofluids by local composition theory The Eyring theory and nonrandom two-liquid (NRTL) equation are used for this purpose The effects of temperature and particle volume concentration on the viscosity are investigated The adjustable parameters of NRTL equation are obtained by fitting with experimental data. The calculated shear viscosities for nanofluids of CuO/water with 29 nm particle size. Al2O3/water with two different particle diameters, 36 nm and 47 nm, and CuO/(ethylene glycol, water) are compared with experimental data and the average absolute deviation (AAD) is 1.2%, while the results from some conventional models yield an AAD of 190% The results of this study are in excellent agreement with experimental data