In order to improve the capacity and rate performance of nickel-metal hydride (Ni-MH) batteries, we proposed a simple phase transformation method to synthesis 3D β-nickel hydroxide nanowires/reduced graphene oxide (β-Ni(OH)2 NWs/RGO) composite. β-Ni(OH)2 nanowires with diameters of 20-30 nm and lengths up to several micrometers were decorated on RGO layers, forming 3D network structure. The 3D β-Ni(OH)2 NWs/RGO composite displayed a discharge capacity of 343.2 mAh/g at 0.2C, and the capacity values has almost no loss after 100th cycles. When the discharge rate was at 5C, the capacity reached a value of 272.7 mAh/g, and its capacity retention was 79.5%. It showed good capacity and rate performance as a positive material for Ni-MH batteries.