A series of π-conjugated poly(aryleneethynylene)s (PAEs) containing two or three different arylene units in the main chain have been prepared by palladium-catalyzed coupling reactions. The PAEs consist of 2,5-dihexyloxy-1,4-phenylene diethynylene (–C C–C 6H 2(OC 6H 13) 2- p-C C–; C 6H 13 = hexyl) units with alternating arylene (–Ar–) units. Various kinds of arylenes, including 9,10-dihydrophenanthrene-2,7-diyl (Phen), pyridine-2,5-diyl (Py), thiophene-2,5-diyl (Th), anthracene-9,10-diyl (Ant), and 2,1,3-benzothiadiazole-4,7-diyl (BTdz), are used as the –Ar– units. The obtained PAEs were soluble in organic solvents by virtue of the attached hexyloxy side chains, and were characterized by NMR, IR, GPC, and UV–vis absorption and photoluminescence (PL) spectroscopy. The cooperation of different polymer segments induces variations in the electronic structure of the PAEs that show π–π∗ absorption peaks in the range of 380–530 nm and PL emission peaks in the range of 430–610 nm with quantum yields of 5–55% in their solutions. The UV–vis and PL peaks of the PAEs shifted to a longer wavelength in films and in colloidal solutions, indicating the occurrence of intermolecular electronic interactions by aggregation. In Ant-containing PAEs, the PL of the polymer chain was entirely replaced with a red-shifted PL emission assignable to the Ant segments due to intramolecular energy transfer.