The anatase TiO2 nanopowders with exposed {100} planes were prepared by a hydrothermal method using H2O2 as morphology control reagent. The structures, morphologies and photoelectric properties of samples were studied by XRD, BET, TEM, UV-vis DRS and PL methods. The exposure of {100} planes is attributed to the introduction of H2O2. More addition of H2O2 leads to larger grain size. The exposed {101} planes are the electron accumulation planes with strong reduction (electron donate) property. The synergistic effect between {101} and {001} planes is unchanged whether {100} planes are exposed, which are shown by the photoreduction test of Ag+ ions. The oxidation (electron gain) ability order among planes, Ag+ and Pb2+ is {100}>Ag+>{101}>Pb2+, as shown by the further photooxidation result of Pb2+ ions. The exposed {100} planes of nanoatatase are helpful to improve the photocatalytic performance by decreasing the electron-hole recombination rate, as shown by the results of UV-vis DRS and PL tests.