Abstract: On the basis of the method of structure identification by Guidorzi,a criterionfor the identification of multivariable system with noise disturbance has beenproposed through the normalization of the vector system and the introduction of theconcept of the correlated and the relative correlated indices.The criterion hasbeen used in the identification of the heating furnace,and the corresponding parameters estimated.The result of the computation shows that it is easier to estimatethe model's parameters with this criterion than with those proposed by Guidorzi and (2).Moreover,it is not affected by the data magnitude and the data length N.