Stroboscopic maps for voltage-mode converters in the continuous conduction mode (CCM) are build up. The stability of one-periodic point is analyzed together with eigenvalues of Jacobian matrix of discrete-maps. The voltage-mode buck converter is taken as an example, and the results of theoretical analysis and numerical simulation coincide with each other, which shows that the stability analysis of the DC-DC converters is feasible using the discrete-map model.