Liquid chromatography and tandem mass (LC-MS/MS) followed with solid-phase extraction (SPE) was developed for simultaneously determining four classes (tetracyclines, quinolones, macrolides and sulfonamides) of ten commonly used veterinary antibiotics in groundwater of Jiaxing city, an important pig breeding base in the Yangtze River Delta region. Samples were taken from 10 typical rural river sections and 21 main urban river sections. Results revealed severe pollution existed in the rural river environment. The total concentration of ten antibiotics was as high as 65.6-467.0 ng x L(-1), among which tetracyclines and sulfonamides respectively ranged in 40.8-253.0 ng x L(-1) and undetected (nd)- 165.0 ng x L(-1), macrolides and quinolones respectively ranged in 3.1-14.68 ng x L(-1) and nd-14.54 ng x L(-1). By comparison, the pollution level in urban rivers was much lower. The total concentration of ten antibiotics ranged in 20.1 ng x L(-1) to 61.2 ng x L(-1), among with tetracyclines varied from undetected to 44.0 ng x L(-1), while sulfonamides, macrolides and quinolones were respectively below 2.7 ng x L(-1), 6.3 ng x L(-1) and 21.6 ng x L(-1).