NOVELTY - A composition contains a high-molecular compound including aryl group-containing structural units (I) and (II), a high-molecular compound including structural unit (I) and bivalent heteroaryl group-containing structural unit (III) or high-molecular compound including aryl group-containing structural unit (IV), and material(s) chosen from a metal material and a carbon material.    USE - Composition is used for electrode for light emitting element and photoelectric conversion element (all claimed).    ADVANTAGE - The light emitting element having electrode formed of the composition, has excellent durability.    DETAILED DESCRIPTION - A composition contains a high-molecular compound including aryl group-containing structural units of formulae (I) and (II), a high-molecular compound including structural unit (I) and bivalent heteroaryl group-containing structural unit of formula (III) or high-molecular compound including aryl group-containing structural unit of formula (IV), and material(s) chosen from a metal material and a carbon material.    m1,n1,m2,n2=1 or more;    Ar1=(n1+2)-valent arylamino residue or (n1+2)-valent aryl (both optionally substituted);    R1=(m1+1) organic group or single bond;    X1=-OM1, -CO2M1, -B(R3)3M1, -N(R3)3Z1, -SO3M1, -SO2M1, -OP(=O)(OM1)2 or -P(=O)(OR3)2;    Z1=anion;    R3=hydrocarbyloxy or hydrocarbyl (both optionally substituted), or H;    M1=N(R3)4 or metal cation;    Ar2=(n2+2)-valent optionally substituted aryl;    R2=(m2+1)-valent organic group;    X2=monovalent organic group containing N, S and/or P;    Ar3=optionally substituted bivalent heteroaryl;and    Ar4=(n1+n2+2)-valent optionally substituted aryl.    When R1 is single bond, then m1 is 1. INDEPENDENT CLAIMS are included for the following:    (1) high-molecular compound, which has fluorene-type structural unit of formula (VII); and    (2) fluorene-type compound, which is of formula (XII).    m3,m4=1 or more;    R4=(m3+1)-valent organic group;    X4=monovalent organic group having lactam structure or monovalent organic group having structure in which heteroaryl ring is directly bonded, preferably monovalent organic group having pyrrolidone structure;    R7=(m4+1)-valent organic group;    X5=X4;and    Y'=chloro, bromo, iodo, p-toluenesulfonate, trifluoromethanesulfonate, methanesulfonate, boric-acid residue or boric-acid ester group.