Abstract: To solve stability problem of large scale systems by using vector LIAPUNOV functions it is necessary to use vector comparison equations. The objective of this paper unlike previous works .which limited to aggregations of linear comparison equations with constant coefficients by means of the Cauchy inequality is to give an approach to aggregate a type of nonlinear comparison equations. On the basis of the stability theorem given in [1], the stability regions obtained here are much larger than those in previous papers.