The degradation effect of electron beam irradiation on clenbuterol hydrochloride was investigated with the method of liquid chromatography-tandem mass spectrometry and infrared spectroscopy. Experimental results showed that the concentration of clenbuterol hydrochloride aqueous solution with original level of 18 ppm and 45ppm decreased with the increase of absorbed dose, and its degradation efficiency was higher than 90% at 5 kGy and 9 kGy respectively. The mass spectrometry showed that −OH and −Cl fell off at low absorbed dose. And with the increase of absorbed dose, the ions such as −NH2, −NH−, −C(CH3)3, −Cl were changed or lost. It indicates that electron beam irradiation could efficiently degrade clenbuterol hydrochloride.Cited