Agaricus bisporus is belonging to family agaricaceae, which is widely acceptable and mostly cultivated among the all mushrooms. It has great nutritional values and it is rich in proteins, vitamins, carbohydrates, fibers, minerals and amino acids. It is effective in antimicrobial, anticancer, antidiabetic, antihypercholesterolemic, antihypertensive, hepatoprotective and antioxidant activities. As it is effective in anticancer property, we check the effects of chemical constituents of Agaricus Bisporus on DNA damaging protein which results its activity PARP inhibiting or vise-versa. We choose the molecular docking technique to check the effects of different chemical constituents of Agaricus Bisporus on DNA damaging protein. For that different PARP inhibitory drugs taken as the standard. We perform the molecular docking of the chemical constituents of Agaricus Bisporus, using 4UND protein with the help of PyRx software and BIOVIA Discovery studio software. Along with that PARP inhibitor drugs also run against the same protein. The results of molecular docking shows the some of the constituents of Agaricus Bisporus has better binding affinity than the standard taken PARP inhibitor drugs. The ergosterol shows the better binding affinity than the niraparib and rucaparib on the same proteins. On other hands the naringenin, quercetin, anthocyanin, folate and myricetin shows the better results than the rucaparib. That means the ergosterol shows the better results as PARP inhibitor than the niraparib and rucaparib.