This article presents a heatline method to analyse the transport mechanism of heat transfer and convective flow of nanofluids in an inclined square enclosure, where a heated thin plate located in the middle of the enclosure. The fluid flow, heat transfer, and heat transport characteristics are illustrated using streamlines, isotherms, Nusselt number and heatlines. Results show that fluid flow and temperature fields strongly depend on Rayleigh number, inclination angle, solid volume fraction, types of nanoparticles and the plate length, and the maximum strength of heatfunction increases as the inclination angle and Rayleigh number increase.