Abstract: The Ractopamine is the beta-agonist. It may be harm to the health of people if it remains excessively high in the animalistic product. The expriement uses the enzyme association immunity method to examine the residual quantity of Ractopamine in some area of Gansu. According to the enzyme association immunity reagent box the Ractopamine to pick out limits is 24 μg/kg of the Ractopamine in pork, obtains the standard curve of the Ractopamine by the Ractopamine six kind of standards the standard curve, examines in the Gansu partial areas by this in the pork the Ractopamine residual quantity whether surpasses picks out limits, and analyzes the different place Ractopamine residual quantity existence different reason.

Key words: ractopamine; ELISA; residues; pork