Polymer fluorescent substance and organic electroluminescence device

A polymeric fluorescent substance having visible fluorescence in a solid state and a polystyrene-reduced number-average molecular weight of 103 to 107, which contains at least one repeating unit represented by the following formula (1) and at least another repeating unit represented by the following formula (3), wherein the sum of the repeating unit represented by the formula (1) is from 5 to 95 mol % of the total number of the repeating units, the sum of the repeating unit represented by the formula (1) and the repeating unit represented by the formula (3) is from 50 to 100 mol % of the total number of the repeating units, and a molar ratio of the sum of the repeating unit represented by the formula (1) to the sum of the repeating unit represented by the formula (3) is from 20:1 to 1:19

• —Ar1—CR1═CR2— (1)
• wherein Ar1 represents an arylene group having 4 to 20 carbon atoms taking part in conjugated bonds and containing at least one substituent represented by the following formula (2) as a nuclear substituent, or a heterocyclic compound group having 4 to 20 carbon atoms taking part in conjugated bonds, and containing at least one substituent represented by the following formula (2) as a nuclear substituent;
• and R1 and R2 independently represent a group selected from the group consisting of hydrogen, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, a heterocyclic compound group having 4 to 20 carbon atoms and a cyano group,
• —(X)m—(CH2)n—Ar2 (2)
• wherein Ar2 represents a group selected from the group consisting of an aryl group having 4 to 20 carbon atoms taking part in conjugated bonds, a heterocyclic compound group having 4 to 20 carbon atoms taking part in the conjugated bonds, and an aliphatic cyclic hydrocarbon compound group having 6 to 20 carbon atoms constituting the ring;
• X represents O or S;
• m represents 0 or 1;
• and n represents an integer of 2 to 10,
• —Ar3—CR3═CR4— (3)
• wherein Ar3 represents an arylene group having 4 to 20 carbon atoms taking part in conjugated bonds or a heterocyclic compound group having 4 to 20 carbon atoms taking part in conjugated bonds;
• and R3 and R4 independently represent a group selected from the group consisting of hydrogen, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, a heterocyclic compound group having 4 to 20 carbon atoms and a cyano group.