A series of highly fluorescent, pyrene-modified oligo(2,7-fluorene ethynylene)s were synthesized and fully characterized. Different emissions were observed between pyrene-end-capped and pyrene-centered oligo(2,7-fluorene ethynylene)s. Moreover, these oligomers were applied to fabricate organic light-emitting diodes (OLEDs), and bright blue or green electroluminescence (EL) with good device performances was achieved in multilayer OLEDs. These pyrene-modified oligo(2,7-fluorene ethynylene)s could be used as optoelectronics materials or models to investigate fluorescent structure-property relationship of fluorene derivatives.