A concurrent desalination and boron removal (CDBR) process and a system thereof are provided. The system includes: a plurality of single-stage reverse osmosis (SSRO) stages connected in series, and a countercurrent membrane cascade with recycle (CMCR). The process includes the following steps: introducing a retentate from one SSRO stage or a series of SSRO stages optimally as a feed to a CMCR; countercurrent a retentate flow and a permeate flow in the CMCR; permeate recycling to a retentate side in the CMCR; retentate self-recycling in at least one of membrane stages in the CMCR; introducing a permeate from the SSRO stage(s) as a feed to an LPMS; and blending permeate streams from the CMCR and LPMS to achieve concentrations in a water product.