This invention relates to high hydrocarbon resistant chemically cross-linked aromatic polyimide polymers, membranes and methods for making and using these polymers and membranes. The high hydrocarbon resistant chemically cross-linked aromatic polyimide membrane described in the present invention comprises a plurality of repeating units of a first aromatic polyimide comprising hydroxyl groups cross-linked with a second aromatic polyimide comprising carboxylic acid groups via covalent ester bonds. These membranes exhibit high permeability and selectivity in separation of mixtures of gases and liquids.