A concept and a (nonlinear finite element) model of how to analyze load distribution of toothed belts having curvilinear tooth profiles for automotive engines at steady states was developed by utilizing a general nonlinear finite element program considering contact problems as well as geometrical nonlinear problems. A toothed belt in the model consists of circularly linked beam elements for endless tension members and two dimensional solid elements for a belt body. A curved pulley surface is supposed to be rigid. Interaction between surfaces of belt teeth and pulleys is considered as moving boundaries. A quite good agreement between experimental and computed results for frictional forces and tooth load confirms that the proposed model is presently the only one practical approach for analyzing load distribution of toothed belts which none of the existing theories can do. Some numerical simulations were performed by changing parameters such as belt pitch, dimensions of teeth and so on.