Abstract: In order to establish the method for Simultaneous determination of 12 elements of boron(B),aluminum(Al),chromium(Cr),manganese(Mn),nickel(Ni),copper(Cu),zinc(Zn),tin(Sn),cadmium(Cd),mercury(Hg),selenium(Se)and lead(Pb)in deep sea fish muscles,HNO₃-H₂O₂-H₂O was used to achieve the complete decomposition of the samples by microwave digestion,the elements were determined by inductively coupled plasma mass spectrometer(ICP-MS). The effects of the matrix were improved by internal standard method to reduce the interference with collision model(KED). Results showed that the detection limit of each element was low and the linear relationship was good,correlation coefficients(r)were at the range of 0.9991~1.0000(Hg was 0.9921),the detection limit was 0.00074~2.2 μg/kg,the quantitation limit was 0.0025~7.1 μg/kg.The method was successfully applied to determine the biological standard elements in scallop(GBW10024). The results were all within the uncertainty range of the certificate. Additionally,the spiked recovery rates of Trichiurus lepturus sample were between 81.8%~110.0%. Different deep-sea fishes sold in the markets were tested with this method,indicating that every fish muscle was low safety risk,the order of content of 4 essential trace elements was Zn>Se>Cu>Cr,in which the content range of Zn was 3.72~22.1 mg/kg,Se was 0.162~0.391 mg/kg,Cu was 0.095~0.334 mg/kg,and Cr was 0.003~0.054 mg/kg.The method was accurate,sensitive and reliable,and suitable for the determination of multi-element concentration in fish muscles,providing technical support for quality control of fish processing;Trichiurus lepturus and Pseudosciaena crocea were rich in Zn,and Psendosciaena polyactis was rich in Se,which were good food sources for pregnant women and nursing mothers.