Nanofluids have enhanced heat transfer capacity compared to conventional fluids. In the present paper, the effects of the thermophysical properties and thermal dispersion on the convective heat transfer coefficients of nanofluids have been investigated. The analytical results show that the effective thermal conductivities of a nanofluid is enhanced with the addition of nanopaticles into the base fluid. The collisions between nanoparticles, fluid molecules, and the wall of flow-tube are intensified, leading to enhanced mixing agitation and turbulence. Improved thermophysical properties and thermal dispersion result in the convective heat transfer coefficient enhancement of nanofluids.