Accurate determination of Cu and Zn isotopes using MC-ICP-MS requires an adequate separation of the elements from bulk samples. Two methods for accumulator dissolution have been investigated through assessments of the purity of Cu and Zn solutions after ion exchange chromatography using AG MP-1 resin, the repeatability of the chromatographic columns, and the consistency of Cu and Zn isotope determination for samples dissolved and purified using different procedures. The results show that: ① Both methods are effective to destroy the organic matter of plant samples; ② The AG MP-1 resin can been used to separate Cu and Zn from the organic sample after effective dissolution, and it is enough for thesample to get the accurate value of isotope composition after one exchangeusing AG MP-1 resin; ③ The standard error of Cu and Zn isotope composition is smaller than the repeatability over a long time, it shows that whole chemical procedure,the separation of resin and the condition of instrument are suitable.