A liquid chromatography_tandem mass spectrometric method was established for the determination of 25 kinds of veterinary antibiotics in manure, soil and water by ultrasonic_solid phase extraction. Purification efficiency of SAX cartridges for soil and manure samples extract and the procedure that manure samples defatted with hexane was also verified. The results showed that the average recoveries of the 25 target antibiotics were 50. 0%-121. 9%, the relative standard deviations (RSD) were 1. 1%-14. 71% (n=9), and the limits of detection (LOD) ranged from 0. 0002-0. 0560 μg/kg for soil and manure and ranged from 0. 002-0. 28 ng/L for water; After adding SAX cartridges, the matrix effects of manure samples reduced to 55%-120%, and soil samples to 75%-160%; after defatting by hexane extraction, the matrix effects of manure sample reduced to 55%-120%. This method has been employed to detect the veterinary antibiotics in environmental samples of livestock farm.