In this article, we consider a three dimensional compressible Navier-Stokes-Korteweg equations with the effect of external potential force. Under the smallness assumptions on both the external potential force and the initial perturbation of the stationary solution in $H^2({\mathbb{R}}^3)\times H^1({\mathbb{R}}^3)$, we prove the global existence and regularity of strong solutions for the Navier-Stokes-Korteweg equations.