Cobalt Oxide and Zinc Oxide nanoparticles were synthesized using extract of Annona muricata (sour soup), leaves as a stabilizing and reducing agents. Cobalt Nitrate and Zinc Nitrate as a precursor. Green method was applicable because low cast, sustainable and ozone friendly. Synthesis of polymer metal Nanocomposites of Cobalt Oxide fictionalized in starch and Zinc Oxide functionalized in starch by using solution casting method. The percentage of Cobalt Oxide and Zinc Oxide Nanoparticles were varied from different concentrations (0. 01, 0. 02, 0. 03,0. 04 with the starch (0. 3,0. 4, 0. 5,0. 6). Structural and Composition of these nanocomposites were characterized using UVVisible, FT-IR,SEM, and XRD. The biological studies of the above composites were evaluated in vitro by using surface inoculation and disc diffusion method. Photocatalytic property of the nanocomposites have investigated by methylene Blue as a dye.