Abstract: The reverse osmosis membrane seed-watermelon juice processing was introduced.The relationship between pressure, temperature, concentration and permeate flux in concentrated process were studied with reverse osmosis.Experimental results proved that the retention of valuable components of this system was approximation 100%.On inorganic salt interception rate was greater than 98%.The end of seed-watermelon juice concentrate concentration was at 20Brix.Case of other things, membrane flux was proportional to the pressure and the liquid temperature.Membrane flux and concentration had an inverse relationship.