Ultrafiltration membranes were prepared using phenolphthalein polyarylethersulfone (PES-C), polyethersulfone (PES) and poly(phthalazinone ether sulfone ketone) (PPESK) as polymers and NMP, DMAc, DMF and DMSO as solvents by immersion precipitation via phase inversion. Experimental data of thermodynamic properties of the polymer solutions and kinetic process of membrane formation were reported. For polymer solutions with good solvents, the sequence of the viscous flow activation energy (Eη) was coincident with that of the viscosity (η), without depending on the dissolving power of the solvents (characterized by intrinsic viscosity ([η])). The cloud point of the dilute polymer solutions was related to [η] of the polymer and gave a strong influence on the gelation rate in membrane formation process. The pure water flux (J) and the bovine serum albumin (BSA) rejection (R) of PES-C, PES and PPESK membranes were measured, the pure water flux (J) of membranes significantly depended on the gelation rate. The open porosity (OP) and the maximum pore size of membrane surface were calculated, and the relationship between membrane performance and membrane pore structure was discussed.