The aim of the study was to find the effect of the antibacterial. Ethanol, chloroform, methanol, acetone, ethyl acetate, hexane, petroleum ether and aqueous extracts of Parthenium hysterophorus from vellore were tested in vitro for their antibacterial activities against, Pseudomonas aeruginosa, Micrococcus luteus and Bacillus cereus with the disc diffusion method. Methanol was the best solution for extracting the effective antibacterial materials from the Parthenium hysterophorus used in this experimental and compared with standard drug, Ciprofloxacin. In the present study show the importance of in producing new bioactivity compounds having antibacterial activity.