A dynamic and thermodynamic model for hot filament chemical vapor deposition (CVD) diamond film growth has been suggested. The chemical reactions in the gas phase, diffusion between different layers of the gas, adsorption and desorption of the gas on the substrate, the growth mechanism and surface reactions, and the interactions among all these factors have been considered. By solving the group of non-linear ordinary differential equations describing the model, we have obtained the partition lines of different regions in the parameter space where single crystal diamond, diamond with some kinds of defects, or graphite grows, respectively. A good agreement between the results of the theory and some experiments has been obtained.