To find out pollution of foods by \%Listeria monocytogenes\%(Lm) and toxicity of Lm. 265 foods belonged to 5 kinds were collected.API bacterial identify system, haemolysis test,PCR and mouse pathogenicity test were used.There were Lm in 4.9% foods.Detectable rate was 15.00%,2.48%,9.52%,4.9% in meats,sausages and quick\|frozen foods respectively.There were no Lm in dairy products and aquatic products.Toxicity determine showed that hemolysin genes determined from hemolysis test,mouse pathogenicity test and PCR had no relationship.Hemolysin genes and internalin genes tests were positive.Lm was sensitive to antibiotic.The sensitive rates of Lm to penbritin and ancef were 100%.