To identify new combination of plant extract with antimicrobial activity the effect of combined aqueous extract of different plant extract like neem (Azadirachta indica), Onion (Alliumcepa) green tea (Camellia sinensis), turmeric (curcuma longa) were tested against Escherichia coli, staphylococcus aureus, Bacillus spp, pseudomonas aeruginosawhich are known to be resistance to various antimicrobes. The inhibitor concentration of extract and combination was determined using broth micro dilation method. The susceptibility of bacteria to combined extract was determined by measuring the diameter of inhibition zones formed around plate after the analysis the combination method done on the four plant neem, onion, green tea turmeric was found to be most showing effect on four bacteria. Escherichia coil, Staphylococcus aureus, Bacillus species, pseudomonas aeruginosa. The result shows that the response of extract was dependent on the concentration used.The enhance of extract concentrationenhance Inhibition Zone.