Abstract: The theory research of the film thickness distribution deposited on hemispherical surface with the evaporation source directly below the substrate is reported. The formulas of film thickness on any position of the hemispherical surface were derived in the geometric disposition. The uniformity of film thickness on the hemispherical surface were analyzed by calculate the relative film thickness. As the distance from the substrate to the evaporation source increase,the coating zone with larger range can be obtained,and the thickness functions turn to analogouslinear functionfrom the exponential function. Finally,a simulation research on the influence of emission pattern of real vapor sourceswas conducted.