1.RO Introduction The reverse osmosis membrane as its name suggests has the opposite direction with the nature permeation, it is a kind of advanced and energy efficiency technology, the work principle is to separate the water and the impurities like ions and germs through the semi-permeable membrane under the pressure greater than permeation pressure. The RO membrane is a kind of semi-permeable membrane and made of polymers via special process. 2.RO Application a)Chemical materials and concentrated liquid recycling; b)Pure water or ultra-pure water productions for industries, medicine and food ; c)Desalination of brackish water and sea water; d)The desalination pre-treatment for boiler makeup water at power plants, thermal power plants and mining enterprises; e)Water for cleaning in pharmacy, electroplate and electronic equipments