The aim of this study is to present a mathematical model for simulating growth of ellipsoidal droplets on patterned substrates. The application of this model will be in studying how to control the size of water droplets formed on the vitreous substrates like glasses, optical lens and car light shields. in this regard, droplets growth on two kinds of patterned surfaces (pillared and sinusoidal substrates) are studied. Up to know the process of dropwise condensation was mostly studied on flat surfaces or surfaces with coatings that has harmful effects on environments.