The aim of the study was to evaluate antimicrobial effect of extract of Lamiaceae plants (Thymus vulgaris L., Mentha spp. and Ziziphora tenuir L.) to prevent growth of pathogenic bacteria (Staphylococcus aureus, Geotrichum candidium) was studied industrial Doogh samples. For this purpose, three levels of concentration of extract that containing (0, 0.075, 0.15 v/v) was prepared. Survival or decrease in the bacterial population in 40 treatments (3 times repeated) in the samples of sterilized Doogh, which that contain a suspension of pure specific strains of Staphylococcus and Geotrichum in the during 24 hours and 14 days by measuring the kinetics of bacterial pathogens was investigated using response surface design. Analysis Results in the inhibition effects of natural antibiotic agent in the Doogh samples revealed that concentrations of thymus extract % 0.14 (v/v), Mentha oil % 0.11 (v/v) and Ziziphora oil % 0(v/v) is the inoculation rate, which in most circumstances Reduction Staphylococcus aureus in 24 h 2.84Log/ml, 7 days in the 1.63 Log/ml. [ABSTRACT FROM AUTHOR]