he collection of evidences have to be done after the mass food poisoninghas happened because of the random of the event.The food safety inspectorsmustdo great efforts to get not only the direct proofs,but also the indirect onesas many as possible to.make correct diagnosis by epidemiological techniques.Thecollection of the patient information and samples of suspicious foods,themethods of analysis and treatment in mass food poisoning were discussed.Author's address Jiang Jiakun,Hygiene and Anti-epidemic Station ofShanghai,Shanghai 200335,PRC