Sulfonated poly(arylene ether ketone ketone sulfone)s (SPAEKKS) copolymers were prepared by aromatic nucleophilic polycondesation. The SPAEKKS membranes were characterization using FT-IR, DSC, TGA and TEM. The water uptake, IEC, transport parameters (H + , Na + and K + ), oxidative and thermal stability and mechanical strength of membranes were comprehensively investigated. This study found that the SPAEKKS-4 showed a good combination of the ion diffusion coefficient (D H+ : 1.01×10 −10 ;D Na+ : 5.85×10 −11 ; D K+: 1.68×10 −10 ), excellent mechanical strength (tensile strength: 55.3MPa; tensile modulus: 1.74 GPa), acceptable water uptake (26–54 wt%), favourable oxidative stability (oxidative stability time reached 29 h) and good thermal properties (T g above 300°C, T d5% above 270°C). It suggested that the SPAEKKS membrane was promising for possible use as an ion exchange membrane.