Abstract: Geoid undulation can be computed from gravity anomalies using Stokes tech-nique. In addition, we can also compute the geoid undulation from gravity disturbances using Hotine's technique. However,even only the gravity anomalies are avalaible we can compute the geoid undulation using modified Hotine's approaches. In this paper, the ellipsoidal solu-tions of the three kinds of Hotine's approaches are presented, Meanwhile, the author also gives a numerical example to illustrate the amplitude of the ellipsoidal corrections of Hotine's formula.