The effect of the component ratio on the permeability and contact angle of ultrafiltration polysulfone hollow fiber membranes modified by interfacial polycondensation of triethylenetetramine (TETA) and isophthaloyl chloride (IPC) has been studied. It has been found that the dependence of the rejection factor on the monomer ratio in the TETA: IPC range from 1: 28 to 20: 1 has two peaks. The first rejection peak is observed in a narrow range of TETA: IPC ratios close to 7: 1. The second peak is observed in a rather broad range of isophthaloyl chloride excess, at TETA: IPC equivalent ratios 1: (5-15). The membrane pure water flux was shown to change conversely to the rejection coefficient. The influence of the average functionality of the system on the change in the selectivity of the modified membranes was studied. A correlation between hydrophilicity and permeability of the modified membranes was revealed: with decreasing contact angle the pure water flux enhances, and the rejection coefficient decreases.