In this study, continuous zirconium(IV) based metal-organic framework (Zr-MOF) membranes were prepared. The pure-phase Zr-MOF (i.e.,, UiO-66) polycrystalline membranes were fabricated on alumina hollow fibers using an in situ solvothermal synthesis method. Single-gas permeation and ion rejection tests were carried out to confirm membrane integrity and functionality. The membrane exhibited excellent multivalent ion rejection (e.g., 86.3% for Ca2+, 98.0% for Mg2+, and 99.3% for Al3+) on the basis of size exclusion With moderate permeance (0.14 L m(-2) h(-1) bar(-1)) and good permeability (0.28 L m(-2) h(-1) bar(-1) mu m). Benefiting from the exceptional chemical stability Of the UiO-66 material, no degradation of membrane performance was observed for various tests up to 170 h toward a wide range of saline solutions. The high separation performance combined with its outstanding water stability suggests the developed UiO-66 membrane as a promising candidate for water desalination.