To optimize the technology parameter for extracting volatile oil from Kalimeris indica with subcritical water,the single factor and orthogonal experiment were conducted by taking volatile oil yield as index,and the bacteriostetic activities of volatile oil were studied.The results were as follows: the yield of volatile oil was 0.50% at 5.0 MPa,160 ℃ for 30 min with the liquid-solid ratio of 20∶ 1(mL∶ g),while the volatile oil yields of Kalimeris indica by steam distillation and Solex extraction method with aether were 0.34% and 0.23%,respectively.Compared with traditional extraction methods,extracting volatile oil from Kalimeris indica using subcritical water has obvious advantage in saving time and extraction ratio.In addition,the volatile oil extracted from Kalimeris indica was found to be possessed powerful bacteriostetic activities to Escherichia coli,yeast and Staphylococcus aureus within the range of experimental concentration.