The objective of this work is to investigate the properties of mixed-matrix membranes composed of polysulfone and mesoporous silica SBA-15 for increased gas permeability without decreased gas selectivity and decreased brittle membranes. Mesoporous silica (SBA-15) was synthesized using nonionic surfactant ethylene oxide/propylene oxide triblock copolymers P123 (EO20PO70EO20) combined with sodium dodecyl (lauryl) sulfate (CH3(CH2)11OSO3- Na+; SDS) as templates. Tetraethyl orthosilicate (TEOS) was used as silica source. Various molar ratios of P123/SDS from 1:0-1:9. Silica structures and silica morphologies were characterized by x-ray diffraction (XRD), nitrogen adsorption analysis and scanning electron microscopy (SEM). Surface of mesoporous silica have been modified with 3-aminopropyltriethoxysilane before mixed with polysulfone. Various weight fraction of SBA-15/PSF from 0 - 40%. The membranes were cast onto a glass substrate using a Doctor Blade. SEM was used to study the morphology of the membranes. Permeabilities of membranes were measured using gas permeable testing and the gases used for permeation measurements were He, CO2, O2, N2 and CH4. The gas separation of membranes were measured using separate He/CO2, CO2/CH4 and O2/N2.The brittle of membranes were measured using tensile tester. Key word : mesoporous silica, polysulfone, triblock copolymers, gas permeable and gas separation