Using Pd(en)2Cl2 as the Pd precursor and graphite oxide as the carbon precursor, the Pd(en)22+ intercalated graphite oxide was synthesized, then it was reduced in solution with NaBH4 and the graphene/Pd nanosized particle composites were obtained. The final graphene composites were characterized by XRD, FE-SEM, TEM, ICP and N2 adsorption test and their H2 storage property was also measured. The results show that the composites have a regular mesoporous structure, and Pd particles with a diameter of 2~6 nm are evenly dispersed between graphene sheets and pillar the graphene sheets to inhibit the accumulation of grapheme sheets. The composites have a high BET surface area and their H2 storage reaches 3.4 wt% at 77 K and 0.11 MPa.