In this paper,the hydrolysis of carbaryl was combined with the diazotization coupling reaction to produce the azoic compounds,which have strong surface-enhanced Raman scattering（SERS） effect.Based on the principle,a novel method for the determination of carbaryl was established using shell isolated Au@SiO2 nanoparticles as SERS substrates which consist of Au nanoparticle cores with a diameter of about 55 nm and the silica shell with its thickness about 1-2 nm.The conditions of the reaction and the method of the detection were optimized.Under the optimal conditions,the linearity was observed in the range of 5.0-100.0 mg/L with a limit of detection of 1.7 mg/L at 1 218 cm-1.The method was applied in the analysis of carbaryl in coconut juice with recoveries of 100.4%-105.1% and relative standard deviations （RSDs） of 2.8%-4.9%.The results indicated that this proposed method was simple,rapid,low-cost and low-consuming.The proposed method was applicable for in situ detection of carbaryl in real samples.