A new method using surface enhanced Raman spectroscopy (SERS) is established for rapid detection of oxytetracycline (OTC) residues in water. In this research,OTR202and OTR103are used as the SERS active substrate,and th e adaptive iteratively reweighted penalized least squares(air-PLS) was used to subtract the fluorescence background of SERS.Then the absorption spectra of colloid and colloidal mixtures and the SERS of oxytetracycline solution are discussed.Finally,the effects of the addition amount of oxytetracycline solutio n and the different mixing time on SERS intensity are analyzed,and the linear regression equation is established between the concentrations of oxytetracyclin e residues in water (X) and the peak area of SERS at 1332cm －1 Y.The results show that a good linearity in the concentration range of 0.1－22.0mg/L is obtained betwe en the peak area at 1332cm－1 and oxytetracycline resi due s in water,Y=5165.7X+4304.9,and the coefficient of determination is 0.9869.The determination coefficient of OTC content in the prediction samples between actua l value and predictive value is 0.9732,and the root mean square error (R MSE) is 1.1122mg/L.Recovery of oxytetracycline residues in water is 96.7%－124.5%,and the relative standard deviation is between 1.2098% and 4.7874% (n=5).This method could meet the detection requirements of oxytetracycline residues in water,and it prov ides a good foundation for the rapid detection of oxytetracycline residues in wa ter on spot.