The objective of this study was to evaluate the antimicrobial activity of four herb extracts from lavender, patchouli, rosemary and eucalyptus possibly used as food preservatives. Minimum inhibitory concentration of France rosemary extracts was 29.1 mg/mL against C. albicans ATCC 10231 and 14.5 mg/mL against B. subtilis ATCC 6613 and E. coli ATCC 25922. Both of France rosemary and American lavender herbal extracts were thermally stable between 40$^{circ}C$ and 121$^{circ}C$ and were stable at only neutral pH. Microbial growth was repressed by adding 2.9 mg of a commercial herbal extracts in 20 mL liquid medium with France rosemary extracts and American lavender extracts.