NOVELTY - A polyimide resin is obtained by imidation-polymerizing a dicyclo hexane type diamine compound (I), a polyoxyalkylene diamine compound (II), a fluorene structure diamine compound (III) and a tetracarboxylic-acid component in presence of a reaction solvent. The molar ratio of content of dicyclo hexane type diamine compound, polyoxyalkylene diamine compound and fluorene structure diamine compound is 95-105.    USE - Polyimide resin is used for polyimide varnish for polyimide molded product (both claimed). Uses including but are not limited to optical fiber, liquid crystal display, organic electroluminescent display, solar cell, polymer optical waveguide, base film of flexible printed substrate, liquid-crystal alignment film and protective film for color filter.    ADVANTAGE - The polyimide resin has excellent solvent soluble property. The polyimide molded product formed using the polyimide resin has excellent transparency, flexible property, bend resistance and toughness.    DETAILED DESCRIPTION - A polyimide resin is obtained by imidation-polymerizing a dicyclo hexane type diamine compound of formula (I), a polyoxyalkylene diamine compound of formula (II), a fluorene structure diamine compound of formula (III) and a tetracarboxylic-acid component in presence of a reaction solvent. The molar ratio of dicyclo hexane type diamine compound (I) is 20-99, polyoxyalkylene diamine compound (II) is 1-40 and fluorene structure diamine compound (III) is 0-40 with respect to tetracarboxylic-acid component (100). The molar ratio of content of dicyclo hexane type diamine compound, polyoxyalkylene diamine compound and fluorene structure diamine compound is 95-105. The tetracarboxylic-acid component is 1,2,4,5-cyclohexane tetracarboxylic-acid dianhydride or its derivative.    R1-R4=H, methyl, ethyl, methoxy or ethoxy;    Y'=direct bond, -CH2-, -O-, -S-, -SO2-, -CONH-, -C(-CH3)2- or -CO-;    R5=H or methyl;    Z=linear or branched 2-4C alkylene;    a-c=0-50;    a+b+c=2-50;and    R6-R9=H, methyl or ethyl.    An INDEPENDENT CLAIM is included for polyimide varnish, which contains polyimide resin and organic solvent.