This paper reports a facile route to synthesize porous carbon nanofibers containing cobalt and cobalt oxide nanoparticles (CoOx/PCNF) as anodes for Li-ion batteries. The Co3O4/PCNF electrode delivers a remarkable capacity of 952 mAh g-1 after 100 cycles and equally excellent rate performance at high current densities. There are several ameliorating mechanisms responsible for the observation: namely (i) high theoretical capacity of Co3O4 particles; (ii) enhanced electronic conductivity and Li ion transfer due to the graphene layers surrounding the Co3O4 particles; (iii) the soft CNF matrix serving as the stress buffer to relieve the volumetric stresses arising from Li ion insertion into the Co3O4 particles. The comparison of electrochemical performance with previous studies based on similar CoO or Co3O4/carbon composite anodes indicates the above value is among the highest.