Abstract: In the present study,the mass spectrometry parameters for determination of ractopamine,salbutamol,clenbuterol and tetracycline were optimized and a high-performance liquid chromatography-mass spectrometry method was established for determination of the above four compounds in livestock tissues.The established method had higher detecting efficiency,sensitivity and accuracy,and its repeatability and recovery rate met the requirement of qualitative and quantitative determination.This method is suitable to be applied in simultaneous quantitative analysis of threeβ-agonists(ractopamine,salbutamol,clenbuterol)and tetracycline in livestock tissues.