Abstract: The presently described subject matter provides a method for reducing boron concentration in a process of desalination of high salinity liquid including passing the high salinity liquid through a first pass reverse osmosis (RO) device to produce a first pass permeate, where at least part of the first pass permeate is treated with a scale inhibitor to obtain a modified first pass permeate being fed into at least one additional RO device to produce at least an additional pass permeate, where the at least one additional pass permeate includes a lower boron concentration than that in the high salinity liquid.