Ultrafiltration was applied in the desalination process of acid-soluble collagen (ASC)from salmon skin. Polyvinylidene fluoride(PVDF)membrane was used in the study for the desalination of collagen solutions with different concentration,when the mass concentration was 1.2%, the rejection rate was 90%.The effect of collagen solution concentration, operation pressure, feed temperature and washing times on desalination process were investigated. Results showed that with the decreasing of solution concentration, increasing of pressure, feed temp...