The influence of three different types of dissolved organic carbon (DOC) on fouling of a PVDF ultrafiltration membrane modified by nano-sized alumina was studied in this work. Raw water was taken from two different locations of the Song Hua River. Some raw water was used directly as the feed of the ultrafiltration experiments. Meanwhile, three different DOC, i.e. hydrophobic fraction, transphilic fraction, and hydrophilic fraction, were extracted by various resins from the raw water and then the adsorbed compounds were eluted using 0.1 mol/L NaOH, respectively. The three compounds were dissolved into distilled water respectively to prepare the feed for further fouling tests, which aim to influence each single compound. The results show that the anti-fouling capability of the PVDF membrane was improved greatly due to the introduction of nano-sized alumina into the membrane structure. Among the three compounds, hydrophilic fraction shows the highest fouling potential, followed by hydrophobic and transphilic fractions.