Abstract: Wire samples using special fixtures,and self-made rod of internal control samples were used to achieve analyze the H08A sample rod of 6.5 mm diameter, adopting a continuous excited mode by the spark discharge atomic emission spectrometry. The uncertainty factors of the method were discussed. And uncertainty evaluation of C,Si,Mn,P and S in the HO8A wire rod electrode samples were carried out, the analytical results of uncertainty met the production testing requirements. The method is suitable for the production on-line testing.