To find out the cause of a food poisoning event, identify the source of infection and risk factors and to control the spread of outbreak.Methods Case research and investigation were carried out adopting the method of field epidemiological investigation. Samples were collected for laboratory test and enterotoxin gene identification. Incubation period was calculated by epidemiological curves to identify the poisoning meal time and food. Results Nausea, vomiting and diarrhea occurred predominantly in 27 confirmed poisoning cases, accompanied by abdominal pain, headache and dizziness in some cases. The poisoning meal time was lunch and supper in December 10^th, and the poisoning food was barbecue rice. The cause of the disease was Staphylococcus aureus enterotoxin A. The similarity of PFGE pattern between strains of Staphylococcus aureus was 100%, sharing high homology. Toxin genes were confirmed as enterotoxin A by RT-PCR.Conclusion The food poisoning occurring in the same place at different meal times was caused by Staphylococcus aureus enterotoxin A. Cross contamination was the most important factor of transmission of Staphylococcus aureus. Supervision should be strengthened in critical control point for restaurants to avoid recurrence of similar incidents.