The extract with the dilution of $50\%$ ethanol and treatment of $121^{circ}C$ for 15min were inhibited highly the growth of staph aureus, Ent. cloacae, Sh. sonnei, A. hydrophila, b. subtilis, St. faecalis and L. casei. of food samples, red-bean dregs with addition of extact of smilax china. leaves or sorbic acid took the similar inhibition effect to microorganisms for the early storage days(1-3days). There was inhibited the growth of microorganisms in strawberry Juice added to 20m1 of $1\%$ extract solution for one storage day in comparison with no addition of smilax china L. Over all with growth inhibition capability to microorganisms and foods, it was believed that the effect and value as the natural food preservatives and the extracts like as this natural plant material took the food safety and it was capable to develop the natural food preservation.