Metal　polyphosphides　are　regarded　as　the　ideal　anode　candidates　for　sodium　storage　because　of　their　high　theoretical　capacity,　reasonable　potential,　and　abundant　resource　alternative.　However,　most　of　them　suffer　from　irreversibility　problems,　as　reflected　by　their　low　reversible　capacity,　inferior　Coulombic　efficiency　(CE),　low　rate　capability,　and　poor　cycling　stability.　In　this　work,　we　systematically　compare　the　electrochemical　behavior　of　a　variety　of　polyphosphides　bulks,　discovering　that　the　CuP2　bulks　have　higher　initial　reversible　capacity　(416　mAh　g(-1)　at　0.1　A　g(-1))　and　CE　(74%)　compared　to　the　FeP2,　CoP3,　and　NiP2　bulks,　which　is　related　to　the　unique　crystal　structure　of　CuP2.　The　CuP2　electrode　is　optimized　by　the　rational　design　of　encapsulating　CuP2　nanoparticles　into　three-dimensional　graphene　networks　(CuP2@GNs),　leading　to　excellent　electrochemical　performance.　In　the　carbonate　electrolyte,　the　CuP2@GNs　electrode　can　deliver　the　reversible　capacities　of　up　to　804,　736,　685,　621,　and　508　mAh　g(-1)　at　0.1,　0.5,　1,　2,　and　5　A　g(-1),　respectively,　along　with　a　first　CE　of　66%.　The　reversible　capacity　can　be　up　to　737　mAh　g(-1)　at　0.1　A　g(-1)　with　a　first　CE　of　83%　in　the　ether　electrolyte.　These　excellent　performance　demonstrates　that　CuP2@GNs　could　be　a　promising　anode　material　for　sodium-ion　batteries.