The alloy Co-P coatings on hollow fly ash spheres have been successfully synthesized through electro less plating in this paper. The possible mechanism of electroless Co-P coating of cenosphere particles utilizing sodium hypophosphite activator was tried. The existence of Co and Co-P were confirmed by XRD (Xray diffraction analysis) and SEM (scanning electron microscopy) images. The cenosphere particles were characterized by energy-dispersive spectroscopy (EDX). The recommendation of coated fly ash for various industrial applications is done.