NOVELTY - An organic semiconductor polymer is new.    USE - In transistor useful for electronic device (claimed) including memory device, electronic paper, radio-frequency identification tag, flat-panel display (e.g. active-matrix flat-panel display, liquid crystal display, organic light emitting diode display, plasma display panel and surface-conduction electron-emitter display), sensor (e.g. photosensor, biosensor, chemical sensor and photochemical sensor), laser device, and photovoltaic device (e.g. solar cell).    ADVANTAGE - The organic semiconductor polymer (I) imparts increased charge mobility, electrical stability and/or air stability. The transistor including the organic semiconductor polymer (I), has increased charge mobility, electrical stability and/or air stability.    DETAILED DESCRIPTION - An organic semiconductor polymer of formula (I), is new.    G1 and G2=-O-, -S-, -Se-, -CR3R4-CR5R6-, -CR7=CR8- or -CR9=N-;    R3-R9=H, F, 1-30C linear or branched alkyl, 3-30C cycloalkyl, 1-20C partially fluorinated alkyl, 1-20C perfluoroalkyl (CnF2n+1), 1-30C linear or branched alkoxy, 3-30C cycloalkoxy, 2-30C linear or branched alkoxyalkyl, 4-30C cycloalkoxyalkyl;    R1 and R2=H, F, 1-30C linear or branched alkyl, 3-30C cycloalkyl, 1-20C partially fluorinated alkyl, 1-20C perfluoroalkyl (CnF2n+1), 1-30C linear or branched alkoxy, 3-30C cycloalkoxy, 2-30C linear or branched alkoxyalkyl or 4-30C cycloalkoxyalkyl;    Ar1=6-30C aromatic ring, 2-14C heteroaromatic ring, or 6-30C condensed polycycle (all optionally substituted) (preferably 7 groups of formulae as given in the specification e.g. group of formula (i));    R20 and R'20=H or 1-20C alkyl;    n=polymerization degree and of greater than or equal to 8;and    a and b=1-3.    Provided that:    (1) when G1 and G2 are -O-, -S-, or -Se-, then at least one of R1 and R2 is a F or 1-20C perfluoroalkyl; and    (2) when G1 and G2 are -CR3R4-CR5R6-, -CR7=CR8- or -CR9=N-, then at least one of R1-R9 is F or 1-20C perfluoroalkyl.    INDEPENDENT CLAIMS are included for the following:    (1) a transistor (10), comprising the organic semiconductor polymer (I);    (2) an electronic device, comprising at least one of the organic semiconductor polymer (I) and the transistor; and    (3) preparation of the polymer (I).    DESCRIPTION OF DRAWING(S) - The figure shows a schematic cross-sectional view of the transistor.    Transistor (10)    Gate electrode (14)    Insulation layer (16)    Source electrode (17a)    Drain electrode (17b)    Active layer including the organic semiconductor polymer (18)