In this work, cellulose nanofiber (CNF) derived carbon and reduced graphene oxide co-supported lithium iron phosphate (LiFePO4, LFP) nanocomposite was prepared by thoroughly mixing CNF with LFP first, followed by mixing again with graphene oxide (GO) to make well dispersed LFP nanoparticles anchored on graphene oxide, finally heating under an inert atmosphere. The ultrathin CNF was used as not only a carbon source but also an adhesive agent which can attach the LFP nanoparticles to the graphene sheets. The LFP nanoparticles were tightly attached to graphene sheets due to the hydrogen bond between GO and CNF. This nanocomposite exhibited good rate performance (discharge capacity of 168.9 mA h g−1 at 0.1C, and 90.3 mA h g−1 at 60C) and long-term cycle stability (~ 91.5% of initial capacity at 10C after 500 cycles) as cathode material for LIBs. The good rate and cycling performances could be attributed to the well-connected electron pathway derived from strongly adhering the LFP nanoparticles to reduced graphene oxide (rGO) and the facilitate electron transportation derived from carbonized CNF (cCNF) conductive network. The introduction of cCNF to LFP/rGO nanocomposite can be a promising strategy for further improve the performance of LFP cathode in LIBs.