NOVELTY - A polymer has weight average molecular weight of 103-108 based on polystyrene conversion, and emits fluorescence in solid state. The polymer has repeating units chosen from arylene group, divalent heterocyclic group and divalent aromatic amine group. An unsaturated hydrocarbon group, which does not contain an aromatic ring, is directly bonded with any one of repeating unit, in terminal(s) of polymer principal chain.    USE - For polymeric composition used for polymeric light-emitting element used as back light of sheet-like light source, segment display device, liquid crystal display and dot matrix display device (all claimed) e.g. computer, television, portable terminal, mobile telephone, car navigator and view finder of video camera, and as pigment for laser, organic solar cell material, electroconductive thin film material and organic semiconductor for transistor.    ADVANTAGE - The polymer has improved stability with respect to electric field reduction.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (i) polymeric composition, which consists of polymer compound or polymer, which emits fluorescence in solid state; (ii) polymeric light-emitting element, which has light-emitting layer containing polymeric composition, provided between electrodes consisting of anode and cathode; (iii) sheet-like light source, which contains polymeric light-emitting element; (iv) segment display device, which contains polymeric light-emitting element; (v) dot matrix display device, which contains polymeric light-emitting element; (vi) liquid crystal display, which has polymeric light-emitting element as back light; and (vii) manufacture of polymer, which involves reacting compound of one or more monomer of formulae: Y1-Ar1-Y2, Y3-Ar2-Y4, Y5-Ar3-Y6 and E1-Y7.    Ar1-Ar2 = arylene, bivalent heterocyclic or bivalent aromatic amine group;    E1 = unsaturated hydrocarbon group which does not contain aromatic ring;    Y1-Y6 = leaving group;and    Y7 = H or leaving group.