Oscillatory behavior for high order functional differential equations

In this paper, the oscillatory behavior for high order nonlinear functional differential equations are studied by means of the Lebesgue measure.It is found thatthe nonoscillatory sclutions only have two kinds on some conditions only have And necessaryconditions for the existence of each kind of nonoscillatory solutions are presented aswell. At the same ime. some sufficient conditions for oscillatory solutions are alsoestablished