The problem of distribution optimization of monopolistic enterprises could be taken as a problem of a network with “directed sides” to change the distribution optimization into a problem of spatial price equilibrium (SPE) with unknown demand function, so that customs equilibrium principle in traffic net optimization could be used.  Dynamic method to solve the model by the means of prediction-correction method is given, after implicit variaritional inequality is presented which equals to spatial price equilibrium.  Its numerical results are also obtained.