The graphitic carbon nitride (g-C 3 N 4 ), as one photocatalyst which possess the suitable band gap, is better for modified TiO 2 and enhanced photocatalytic degradation of organic pollutants. In this work, the g-C 3 N 4 /TiO 2 were successfully prepared via directly calcined the mixture of melamine and P25. The as-prepared g-C 3 N 4 /TiO 2 photocatalysts were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM) and high resolution electron microscopy (HRTEM), Raman and Fourier transform-infrared spectroscopy (FT-IR). The photocatalytic performances of g-C 3 N 4 /TiO 2 composites were investigated by degradation of ciprofloxacin. The results showed that the g-C 3 N 4 and P25 were successfully composited, and the bond of C–N was well formed, the calcined temperature for as-prepared photocatalysts and the ratio of melamine and P25 were important to the degradation rate of ciprofloxacin. When the mixture of melamine and P25 with 1:2, and calcined temperature at 600°C, the degradation rate of ciprofloxacin could reach 95% in 60min. The enhanced photocatalytic performances could be mainly attributed to the suitable band gap structure with heterojunction of CN-P25. Finally, the possible transferred processes of photoelectrons and photoholes were proposed.