In this paper, we obtain some sufficient conditions to guarantee the uniform asymptotic stability of zero solution and bounded of all solutions to nonautonomous delay differential equation of third order ...when p(t, x(t), x(t − r),ẋ(t),ẋ(t − r),ẍ(t)) = 0 and p(t, x(t), x(t − r),ẋ(t),ẋ(t − r),ẍ(t)) = 0, respectively. By using the Liapunov functional approach, we prove two new results on the subject.