NOVELTY - Organic electroluminescent compounds (Q), are new.    USE - (Q) are useful: as an organic thin film layer in organic electroluminescent device (all claimed) that is useful in flat panel display of a wall-mounted TV, copy machine, printer, and LCD including light source, display panel and beacon light; in electrophotographic photosensitive member, photoelectric conversion element, solar cell and image sensor.    ADVANTAGE - (Q) have excellent thermal stability, power efficiency, driving-voltage characteristic and electronic transportation ability, and is free from steric hindrance and molecular association by its quenching concentration. The organic electroluminescent device consumes reduced electric power, operates in low voltage, and has broad color reproduction range.    DETAILED DESCRIPTION - Organic electroluminescent compounds (Q) of formulae (I) or (II), are new.    R1-R14 = 1-60C-alkyl, 6-60C-aryl, 3-60C-heteroaryl, 1-60C-alkoxy, 6-30C-aryloxy, 1-20C-alkylamino, 6-30C-arylamino, 1-20C-alkylsilyl, 6-30C-arylsilyl, 1-50C-arylalkylamino, 2-60C-alkenyl, 2-60C-alkynyl, OH, nitro, amidino, hydrazine, hydrazone, carboxyl or its salt, sulfonic acid or its salt, phosphoric acid or its salt, 3-60C-cycloalkyl, 5-60C-aryl, cyano, halo or H (all optionally substituted), where two substituents of R1-R5 groups are connected with middle unit of K to form a condensed ring;    K = divalent group of formulae (a) or (b);    Q = CR15R16, NR17, O, Se, P, S and SiR18R19;    Z = CR20R21, NR22, O, S and SiR23R24;    R15-R24 = H, D, 1-60C-alkyl, 6-60C-aryl, 3-60C-heteroaryl, 1-60C-alkoxy, 6-30C-aryloxy, 1-20C-alkylamino, 6-30C-arylamino, 1-20C-alkylsilyl, 6-30C-arylsilyl, 1-50C-arylalkyl amino, 2-60C-alkenyl, 2-60C-alkynyl, OH, nitro, amino, amidino, hydrazine, hydrazone, carboxyl or its salt, sulfonic acid or its salt, phosphoric acid or its salt, 3-60C-cycloalkyl, 5-60C-aryl and cyano, where substituents of R15-R24 bonded to each other to form condensed ring;    m = 0-4;    X1, X2 = CRR;    L = single bond partially substituted 1-60C alkenylene, partially substituted 2-60C alkenylene, optionally substituted 2-60C-alkynylene, optionally substituted 3-60C-cycloalkenylene, N, O, and S, 2-6C-heterocycloalkyl, 6-50C-arylenen and 3-50C-heteroarylene;    Y1 = CR1bR1b, O or S;    n = 0-1; and    R, R1b = H, D, 1-10C-alkyl, 1-10C-alkyl, 6-60C-aryl or 2-60C-heteroaryl.    INDEPENDENT CLAIMS are included for:    (1) organic thin film layer comprising (Q); and    (2) organic electroluminescent device comprising a light-emitting layer, a hole injection layer, a hole transport layer, a hole blocking layer, a electron transport layer, a electron injection layer, a electron blocking layer and the organic thin film layer.