As high molecular weight amine were able to extract trace cadmium, copper and lead Into an organic phase at the potassium iodide-sulfuric acid, simultaneously, conditions for determination directly organic phase with atomic absorption spectrophotometry were investigated. By setting potassium iodide concentration and sulfuric acid concentration at 0.2M and 3.6 N, respectively, cadmium, copper and lead were extracted with 5v/v% Amberlite LA-2-n-Buthyl acetate solution simultaneously. Under the conditions above described, the extraction rate of cadmium, copper were 100% and its of lead was 98%. The coefficient of variation were proved to be 0.71%, 1.47%, 1. 30%; which were obtained by the 20 repeats of determination with 1 micro g/ml cadmium, copper solution and 5 micro g/ml lead solution With regard to the effect of coexisting ions, alkaline metals, alkaline earths metals, Fe(II), Zn(II), Al(II), Mn(II), Cr(IV), Si(IV), Ni(II), As(III) etc. did not interfere. The method was applied to the determination of cadmium, copper and lead in hair with satisfactory results.