Titanium dioxide/reduced graphene oxide nanocomposites (TiO2/RGO-X, X=S, T or C, was denoted sodium dodecyl benzene sulfonate, Triton X-100 and cetyl trimethyl ammonium bromide, respectively) were synthesized using a one-step surfactant-assisted hydrothermal method. The characterization of phase structure and morphology of the as-obtained nanocomposites reveals that TiO2 in the TiO2/RGO-X exhibits the morphologies of nanoparticles, nanowires and array-like nanowires on the surface of RGO, respectively. Compared with the control TiO2/RGO nanocomposite, TiO2/RGO-X presents an excellent photocatalytic activity. With uniform array-like TiO2 nanowires on the surface of RGO, the TiO2/RGO-C shows a significant enhancement in the photocatalytic efficiency. Besides, a deeper insight into the growth mechanism of TiO2/RGO nanocomposites is put forward. This work indicates that the surfactant-assisted hydrothermal method is an effective approach to improve the structure, morphology and photocatalytic performance of TiO2/RGO composites. Moreover, the surfactants with various types can interact with the precursors of TiO2 and RGO in different ways.