The research about the right inverse of linear partial differential operators P(D) with constant coefficient is very important for studying the properties of the solutions.The Phragmén-Lindelf condition has given a method to study the existence of right inverse of linear partial differential equations with constant coefficient.The perturbations for Phragmén-Lindelf condition with two independent variates in some case was mainly discussed

and a necessary condition of pertu bations of Phragmén-Lindelf condition in the case was given.