In this paper, a fuel cell/lithium battery hybrid system for portable applications is developed, the system includes a polymer electrolyte membrane fuel cell stack, two hydrogen canisters, a lithium battery, a DC/DC converter cascaded to fuel cell and control electronic subsystem. The hardware circuit is designed for the system and the software program is written to realize the energy management of the hybrid power system, keeping the fuel cell in a good working condition under the precondition of satisfying the load power demand. The dynamic and static characteristics of the system are tested, and the tests show that the hybrid system allows the output of fuel cell to be buffered when handles sudden load changes. Energy management strategy can increase life span of the fuel cell because it avoids the counter-polarization of fuel cell during load mutation.