Equations of excitons in columned composite systems composed of quantum dots and quantum wires have been formulated. Then the energy of excitons is solved by the perturbation theory. From the example of CdS/HgS/CdS/HgS/CdS columned composite systems composed of quantum dots and quantum wires, the electric probability distribution in this system and the dependence of energy of excitons on the size of system are studied. The results show that：(1) The energies of electrons, holes and excitions in this system all decrease as the height, h0, of quantum dots increases and the impact of the interaction of electrons holes to the energies of the ground excitons is greater than that of the excitons. (2) The probability distribution of the electrons is undulating in the ridial direction, and the probability tends to zero on the axis and near the surface and is maximal near R/2. The probability distribution of electrons is vibratory near the quantum dots in the axial direction.