Blending polymer CA/PSf was prepared using N.N-dimethylacetamide (DMAc) as solvent and PEG400 as an additive in membrane fabrication. The phase inversion method using immersion precipitation process was carried out to make the membrane CA/PSf. Membrane CA/PSf characterized by measuring the contact angle of the membrane to determine the membrane hydrophilicity. Performance of membrane is measured using water flux and rejection of dextran 70 kDa and Bovine Serum Albumin (BSA) 67 kDa. The contact angle of the membrane CA/PSf which amounted to 50° until 63°, so it can be categorized as hydrophilic membranes, because the value of the contact angle is lower than 90°. The resulting water flux membranes CA/PSf from 3.8708 L.m−2.h−1 to 10.462 L.m−2.h−1. Dextran rejection generated which is equal from 40.24% to 89.53%, while the BSA rejection of membrane from 36.21% to 81.68%. Increasing the composition of PSf produces contact angle and water flux increased, but the rejection of dextran and BSA decreased. Resilience fouling membranes CA/PSf is measured by Relative water Flux Reduction (RFR) and Fouling Resistance. RFR membranes CA/PSf which amounted from 9.445% to 32.75%, while the membrane fouling resistant CA/PSf ranged from 0.6725 to 0.9055. RFR is higher when the amount of PSf increased and indicating that their membranes are prone to fouling, it also can be evidenced by the decreased value of resistance fouling when the composition of PSf increase.