We report the sequential polyol synthesis of Co3O4@ZnO nanocomposite. Firstly, Co3O4 was synthesized and ZnO was produced on the surface of the as synthesized Co3O4 NPs in the same pot. The nanoparticles have been investigated by powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscope (TEM), and physical properties measurement system (PPMS) of Quantum Design. The weight percentage of phases were found as 26.3 % for ZnO and 73.5 % Co3O4 (crystal thickness ratio ) by using the generalized reference intensity ratios (RIRs) method. Superparamagnetism in Co3O4@ZnO nanocomposite at room temperature was first detected with high Ms value of 10 emu/g, and the non-hysteric curve with nearly saturated nature at high fields. This non-hysteric and nearly saturated nature at 15 kOe is the nature of superparamagnetic structures.