Abstract:We consider the following neutral functional differential equation with piecewise constant delay:d2/dt2(x(t)+p(t)x(t-1))=qx(2[t+1/2])+g(t,x(t),x[t])By using fixed point theorem and the method of pseudo-almost periodic sequence, we get the existence of the pseudo-almost periodic solution of this equation. Also, some results in reference [5~8] have been extended.