We report the synthesis of a new conjugated compounds, tris-[4-[10-(4-tert-butylphenyl)-10H-phenothiazin-3-yl]phenyl]amine[TPPPA]. TPPPA showed UV-visible absorption maximum value of 352nm and photoluminescence (PL) maximum value of 455nm. It was found that TPPPA could be applied to HIL material by HOMO level calculation from cyclic voltarnmetry data. Organic light-emitting diodes (OLEDs) device with configuration of ITO/TPPPA(60nm)1 NPB(15nm)/Alq(3) (70nm)/LiF(1nm)/Al(200nm) exhibited a current efficiency 2.85cd/A and power efficiency of 1.18lm/W at 10mA/cm(2) current density.