Poly (ether sulfone)-(PES) based mixed-matrix nanofiltration (NF) membranes were fabricated by incorporating carbon nanofibers (CNFs) through solution casting technique. Scanning optical microscopy (SOM), scanning electron microscopy (SEM) and surface roughness analysis were carried out in membrane characterization. Water uptake, contact angle, tensile strength, and porosity measurements, as well as water flux, salt rejection and antifouling experiments were used. SEM images showed more porous structure for the blended membranes compared to virgin membrane. Finger-like pores was also observed for the modified membranes. SOM image showed uniform surface for the prepared membranes relatively. Surface roughness also showed decreasing trend by increase of CNF ratio. Water contact angle was reduced from 67.8o for pristine membrane to 54.6o for the blended membranes. Salt rejection also increased from 66.49% for bare membrane to 86.4% for the blended membrane containing of 0.1 wt% CNFs. The membrane porosity, water content, water flux and tensile strength were enhanced by using CNFs into the membrane body. Blended PES-CNFs membranes showed high fouling resistance compared to the virgin membrane. The flux recovery ratio was measured up to 79.20% for the modified membranes.