Abstract: In fluorescent X-ray analysis of Steel sample, matrix effect must be corrected using Lachance, De Jongh and JIS models. This three correction factors exit definite relation. Lachance model's α and De Jongh model's α may exchange each other. The α_B used in Lachance α and De Jongh models may transfer into d's used in JIS model. The value of Ei computed from theoretical correction factor α_i. used in Lachance model is same as found from calibrate curve, and the correction factors d^* used in De Jongh and JIS models covered from Lanchance mondel, α_B is same as computed directly by individual ternary sample method.