In the framework of dynamical mean field theory (DMFT) we analyze Hall effect in doped Mott insulator as a parent cuprate superconductor. We consider the partial filling (hole doping) of the lower Hubbard band and calculate the dependence of the Hall coefficient and Hall number on hole doping, determining the critical concentration for sign change of the Hall coefficient. Significant temperature dependence of the Hall effect is noted. A good agreement is demonstrated with the concentration dependence of the Hall number obtained in experiments in the normal state of YBCO.