A method for preparing a conjugated microporous polymer comprises the coupling of an alkynyl aryl monomer having a plurality of terminal alkyne groups with an iodo- or bromo-aryl monomer having a plurality of halogen atoms in the presence of a palladium (0) catalyst. The conjugated microporous polymer comprises nodes comprising at least one aryl unit and struts comprising at least one alkyne unit and at least one aryl unit, wherein a node is bonded from its aryl unit or units to at least two struts via alkyne units. Such polymers are useful in numerous areas such as separations, controlled release, gas storage and supports for catalysts.