By using dynamic programming (DP) which is a kind of global optimization algorithm, an energy management control strategy for a parallel PHEV on different charging depleting range (CDR) had been studied. The results show that motor-dominant control strategy should be applied to the PHEV when CDR is less than 55km, and engine-dominant control strategy should be used when CDR is more than 55km. With optimal control strategies from DP, the best economic performance can be obtained as CDR is 55km; PHEV average equivalence fuel consumption can be reduced to 2.9L/100km which is 63% lower than that of prototype vehicle.