In this paper, we determined the solubility parameter of five novel polyaryl ether sulfone ether ketone ketones( PESUEKK)containing naphthalene ring hy turbidity titration method, with chloroform as solvent and n-hexane and methanol as precipitant. The results showed that the mentioned method was easy and effective for the determination of the solubility parameter of PESUEKK. The solubility parameter of PESUEKK at 20℃ was 20.21 - 21.02(J/mL)1/2, which was of great importance to the study of the solution beh...