Synthesis of TiO2/ZnO nanocomposites (TZN) through one-step refluxing method for photochemical degradation of humic acid (HA) in aqueous solution has been studied. Titanium isopropoxide (TTIP) and ZnSO4.7H2O were used as a starting material under base solution at 120 oC for 24 hours. TZN materials were characterized by x-ray diffraction (XRD), scanning electron microscope (SEM), and differential thermal analysis (DTA). The characterization showed that there is a specific diffraction peak from TiO2 (2θ = 25.30) and ZnO (2θ = 36.33) as a composite with the crystal size 41.55 and 15.76 nm, respectively. The material morphology showed the granular shape of the composite and have a good thermal stability. The photochemical activity was evaluated by photocatalytic degradation of HA under UV254 light. The optimum condition was found at pH 4.0, and times at 30 minutes. This study confirmed that the TZN material can decrease the HA concentration. Furthermore, the maximum result of the experiment was a 95-98% degradation of HA in aqueous solution.