NOVELTY - An organic compound having electron-transporting and/or hole-blocking performance, where the organic compound is one of multi-aryl substituted pyridine derivatives is new.    USE - As emitting material, hole-blocking material and electron-transporting material; in organic semiconductor devices such as organic light emitting devices (OLEDs)(claimed) such as organic transistor, organic integrated circuit, organic solar cell, organic laser, organic sensor, doping fluorescent device, phosphorescent device and white OLEDs.    ADVANTAGE - The compounds are easy to prepare, and thus are economically attractive. The OLEDs which use the organic compound as electron-transporting layer (ETL) and/or hole-blocking layer (HBL) provide good color purity and improved efficiency. The OLEDs possesses improved efficiency and narrow emission band.    DETAILED DESCRIPTION - An organic compound (C1) having electron-transporting and/or hole-blocking performance, where the organic compound is one of multi-aryl substituted pyridine derivatives represented by the following formulas (I)-(VI) is new.    R1=1-20C alkyl, 3-20C cyclic alkyl or 1-20C alkoxy (all optionally substituted), H, 7-50C aralkyl, 6-50C aryl, 6-50C aryloxy or 5-50C heterocyclic aryl;    R2,R'2,R5,R'5=H, carboxyl, fluorinated methyl, cyano, nitro or 2-20C ester (and at least contain one of carboxyl, fluorinated methyl and cyano group);and    Ar1,Ar'1,Ar2,Ar'2=6-50C aryl or 5-50C heterocyclic aryl.    An INDEPENDENT CLAIM is included for an organic light emitting device (OLED) comprising anode, cathode, an emitting layer disposed between the anode and the cathode, at least one hole-transporting layer disposed between the anode and the emitting layer, at least one electron-transporting layer disposed between the cathode and the emitting layer, optionally at least one hole-blocking layer between the emitting layer and the electron-transporting layer, and a substrate present on either the anode or cathode, where the electron-transporting layer comprises the organic compound (C1) or the hole-blocking layer comprises the organic compound (C1).