Abstract: This paper started from the concept of traceability and studied the system of food safe examination traceability and its function to inquire into the accuracy and efficacy that food safety examination could result with reliability. Food safe examination result validity comes result reliability. The result comes reliably from the commensurability. The result commensurability comes from in the food safe examination may trace to the source. Speaking of a country, all examination result all should trace to the source in the national datum (or standard); Speaking of world, then should trace to the source in the international datum (either standard) or the corresponding agreement standard.

Key words: food safety, trace ability, reference material, examination