The evaluation of uncertainty in environmental elemental analysis can be difficult because of the wide variety of analytical sample and objectives. for the specification of measured, elemetal analysis need certain method and high pretreatment technique. The sample of Pb, Cd in paddy soil and sewage sludge were analyzed by same ICP-AES, but each using four different pretreatment technique ; 0.1N HCl extraction, AB-DTPA extraction and two Mixture Acid Digestion. The four technique gave comparable results for the analysis of lead and cadmium. Concentrations determined by Mixture Acid Digestion were more higher than those by 0.1NHCI extraction and AB-DTPA extraction.