I Periodic Boundary Value Problem For Integrodifferential Equations In Banach Space

In this dissertation, we study the following periodic boundary value problems (PBVP) for integrdiiferential equations in a order Banach Space E.We consider the new situation, that is the lower solutions are not less than upper solutions , on the basis of comparison result , and fixed point theorems of increasing operator, using the monotone iterative technique . We have got the extremal solutions of PBVP (1),(2).