Linear conjugated fluorene derivatives (TetF and DiF) were synthesized. The bulky substituents attached on each fluorene moiety are expected to suppress the quenching processes from exciton state by preventing the aggregation effect.([1]) The TetF and DiF showed UV0visible absorbance and photoluminescence (PL) in the ranges of 315-350nm and about 390nm. Electroluminescence (EL) maximum of OLEDs using DiF was shown at 410nm corresponding to the pure blue emission. Also, new emission appeared at 420nm. Adequate balancing of the hole and electron transport layers (HTL, ETL) can enhance the luminance and efficiency of the OLEDs. The injection of HTL does not affected in emission range of devices. The emission of devices with ETL was dependent on the thickness of ETL. The Alq(3) and PBD were used as ETL.