Coumaric acid is widely found in plants and vegetables such as green peppers, carrots, tomatoes, and strawberries. The coumaric acid has different degrees of inhibition on Staphylococcus aureus, Shigella, Escherichia coli and Pseudomonas aeruginosa, and also has a blood lipid lowering effect. The coumaric acid can seize the nitrate, so that the nitrate has no chance to become a carcinogenic nitrite, thereby preventing the occurrence of gastric cancer.