Spatial position of lipid domain of liquid-disordered/liquid-ordered (Lo/Ld) phase separation in a giant unilamellar vesicle (GUV) was controlled by physical confinement in microchannels. The confinement allowed to determine free curved regions where the lipid domains of the minority phase, either Ld or Lo, became kinetically trapped and favorably accumulated, fused and grew to create single domains at the prescribed areas. The confinement in straight channels and in between pillars reproducibly led to polarized GUVs from one pole to multi poles, depending on the design of microchannel. The approach enabled multiple GUVs confinement, advantageously giving access to data with statistic relevance. The method is also technologically simple, only requiring single-layer microfluidic chips that can be purchased or custom-built through conventional microfabrication procedures, offering both accessibility and versatility. As such, it is readily extendable to other types of geometries to spatially control specific lipid domains, domainspecific membrane-associated proteins and/or nucleic acids in a user-defined fashion. We thus anticipate that it will allow shading light on dynamic membrane reorganization process in model membrane systems as well as constitute a valuable tool for building synthetic cells with better spatio-temporal control over their component distribution.