The geoid is defined as the equipotential surface of the Earth�s gravity field, which coincides onaverage with the mean sea level of the Earth. This study is motivated by the fact that densityheterogeneities within the Earth�s mantle give rise to geoid undulations. Subducting slabs are expectedto dominate the mantle heterogeneity structure as they are colder and denser than the ambient mantle.We model the global geoid from subducted slabs in the upper mantle for the past 140 Ma at an intervalof 40 Myr for 3 different radial viscosity structures. The models predict geoid highs above subductionzones whereas geoid lows are somewhat scattered. The modelled positive geoid anomaly is as high as110 m, and the negative anomaly is as low as -40 m. We have compared the present-day geoid from ourmodels with that from upper mantle slab model RUM [Gudmundsson & Sambridge, 1998] and findthat the correlations are 0.74, 0.65 and 0.80 for the three viscosity structures. As the correlations arequite good, we infer that the reconstructed subduction zones when run forward in time in our modelscan match the present-day geoid from the observed subduction zones. We also found that even if westart with the same density structure, the geoid models differ from each other based on different radialviscosity structures, and therefore the details of radial viscosity variations have important effects on thegeoid.