Abstract: Summary This paper is about when determined trace copper in food with Furnace Atomic Absorption Spectromesry, the Ashing and Extraction processes which before experiment had been simplified the result of determination were very pleased. The influence of the Ash temperature and Atomization temperature, concentration of nitric acid and coexst element-polassium, Sodium, Calcium, Magnesium on the result of the determination of copper had been discussed. And a different kind of food samples had been determined. Add rate of recovery was 83.8-106%, R.S.D was 5.4%.