Oyster mushroom( Pleurotus ostreatus) is belong to the group of healthy foods, as they contain high levels of proteins, vitamins and different classes of compounds, it is discovered that oyster mushrooms could play a key role in maintaining good health. Oyster mushroom (Pleurotus sp.) Class Basidiomycetes and Family Agaricaceae are widely known as ‘dhingri’ in India. Pleurotus Ostreatus have several medicinal properties including ; anti-arthritic , antitumor, immune modulatory , antioxidant, anticancer, anti-inflammatory, antigenotoxic, hypo-cholesterolaemic, antihyperglycaemic antihypertensive, antiplatelet aggregating, antiviral and antimicrobial activities.. In this paper studied that effects of chemical constituents of oyster mushroom(Pleurotus sp.) on DNA damaging protein which analyzed its activity of PARP inhibiting or vice – versa.For this analysis we choose the molecular docking technique to check the effects of different chemical constituents of oyster mushroom(Pleurotus sp.) on DNA damaging protein and compare their results to PARP inhibitory drugs which taken as standard . We perform the molecular docking in between chemical constituents of oyster mushroom(Pleurotus sp.) and 4UND protein compare to performance of molecular docking in between standard PARP inhibitory drugs and 4UND protein with the help of PyRx and BIOVIA Discovery studio software.The analysis of molecular docking shows that some chemical constituents of oyster mushroom(Pleurotus sp.) having more binding affinity than standard PARP inhibitory drugs .The Rutin shows better binding affinity than PARP inhibitory drugs on the same protein.