Abstract: The purpose of this work is to fabricate porous iPP membrane with uniformly dispersed PLA porous particles inside. In order to extend its application in biomedical field, surface hydrophilic modification was carried out. In this study, iPP - PLA (poly (lactic acid)) blend hollow fiber membranes were prepared via thermally induced phase separation (TIPS) method and PLA surface ester group hydrolysis under alkali solution was applied to improve its hydrophilicity. The effect of different diluent mixture ratio on the mechanical properties was measured and compared by tensile strength tests. For further evaluation of potential biomedical application in blood gas separation like membrane oxygenator, O2 and CO2 gas permeation properties of the iPP–PLA membrane was investigated, and optimized fabrication parameter was then selected. Water contact angle was measured to indicate hydrophobic to hydrophilic change after surface alkali hydrolysis. The SEM was used to characterize the morphology of the membrane and the results showed that in iPP–PLA blend system, with MAH-g-PP as surfactant agent, partially miscible was observed and porous PLA particles, also formed via TIPS, dispersed in iPP matrix uniformly with 10-20 μm in size. Mechanical property measurements showed that iPP–PLA membrane demonstrates larger elongation at break than iPP membrane and biggest gas permeation rate was achieved with 5:5 diluent ratio. After hydrolysis, smaller water contact angle of iPP–PLA hollow fiber membrane surface indicates significantly hydrophilic improvement.