Abstract: In this paper we discussed the existence of periodic and almost periodic solutions of a class of second order differential equation. Under the assumption that g is a continuous homeomorphism, we have proved using fixed point theorem twice that the equation has a uniqueTperiodic solution ife(t)is aTperiodic function. Furthermore we have proved using approxi mation method that the equation has almost periodic solution ife(t) is an a lmost periodic function.

Key words: second order differential equation, periodic solution, almost periodic solution