It is demonstrated that the incorporation of reduced graphene oxide (rGO) and pseudocapacitance materials often offer an effective strategy toward fast reversible redox reactions while remaining their high pseudocapacitance. In this work, a type of rGO-modified Ni-Co phosphates (Ni(Co)NH4PO4@rGO) microplates were fabricated for supercapacitors electrodes via a one-step hydrothermal method. SEM and TEM tests indicated that the obtained microplates are comprised of well-aligned crystalline Ni(Co)NH4PO4 nanosheets. Moreover, the rGO-modified microplates exhibit a high specific capacitance of 1020 F g−1 at 1 A g−1, which is 16.3% enhanced compared to that of the untreated Ni(Co)NH4PO4) ones (877 F g−1). While the rate capacitor can reach to 92%. Furthermore, it is observed that after 700-cycles, the specific capacitance can increase to their maximum value of 1451 F g−1 at current density of 10 A g−1, and can still remain 1275 F g−1 after 5000 cycles, showing a high cycling stability. The Ni(Co)NH4PO4 showed the same tendency but the low values. These excellent electrochemical performances could be due to rGO modification and self-assembled well-aligned nanosheets. This type of structures cannot only facilitate the transfer electrons, but also offer high electrochemical activity sites and short transport path length for electrolyte ions.