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The use of antibiotic drugs is associated with problems, such as unwanted side effects and drug resistance, and the lack of new and natural antimicrobial drugs that have fewer side effects than antibiotics. The aim of this study, investigating the effects of hydroalcoholic extract of sour lemon peel on a few of standard strains of G⁺ and G^- bacteria. Concentrations of 25,50,100 and 200 mg/ml of extracts by percolation method were prepared to determine antibacterial effects and using a well publication method against ten different species of G+ and G- bacteria, then the Minimum Inhibitory Concentration of bacterial growth (MIC) and Minimum Bacterial Concentration (MBC) were evaluated by dilution in tube. Alcoholic extract of sour lemon peel in a dose-dependent manner significantly increased the diameter of zone to inhibit the growth of  the bacteria, especially G+ bacteria, as compared to G- (p <0.05). In the concentration of 200 mg/ml, the maximum and minimum diameter of the inhibition zone was 20 mm for Streptococcus pyogenes and 12 mm for salmonella typhimurium, respectively. MIC and MBC methods had the strongest effect on Streptococcus pyogenes and had the least effect on Escherichia coli and Salmonella typhimurium. Extract of sour lemon peel has a significant antimicrobial effect, which can be used as an alternative to synthetic antibiotics with increasing microbial resistance.