In this paper, a series of magnetic Stearic acid (Sa)/Fe3O4/TiO2 nanocomposites were synthesized as a functional phase change materials through a two step methods; sol gel method followed by dispersion technique. Fe3O4/TiO2 nanocomposites were first synthesized by varying the molar ratio of Fe3O4 :TiO2 from 1:1 to 1:5 followed by dispersing the synthesized Fe3O4/TiO2 nanocomposites in stearic acid (Sa). The structural properties were confirmed by X-ray diffractometer (XRD), while their chemical compositions were determined from energy dispersive X-ray (EDX). The molecular interaction were detected by Fourier transform infrared spectroscopy (FT-IR). Thermal-storage capability such as latent heat and specific heat were detected by differential scanning calorimetry (DSC) while high thermal reliability of their phase-change performance were detected by thermogravimetric analysis (TGA) experiment. The result shows that the incorporation of nanocomposites Fe3O4/TiO2 enhance the latent heat as well as heat capacity of phase change materials.