NOVELTY - A binder resin composition comprises polymer (A) having carbonyl group-containing structural unit (I), water-insoluble particulate polymer (B-1) and/or water-soluble polymer (B-2). The polymer (B-2) has acidic group and/or its salt.    USE - Binder resin composition is used for electrode for lithium ion secondary battery (claimed). Uses include but are not limited to mobile telephone, video camera, notebook computer, hybrid vehicle and electric vehicle.    ADVANTAGE - The binder resin composition has excellent binding property. The electrode obtained using binder resin composition has excellent flexibility and suppressed uneven distribution of active material or binder. The battery obtained using binder resin composition has excellent battery characteristics and long-term cycling characteristics. The slurry for electrodes has excellent stability even when using for negative electrode.    DETAILED DESCRIPTION - A binder resin composition comprises polymer (A) having carbonyl group-containing structural unit of formula: -(CH2-CH(-N(-R1)-C(=O)-R2))- (I), water-insoluble particulate polymer (B-1) and/or water-soluble polymer (B-2). The polymer (B-2) has acidic group and/or its salt.    R1,R2=H or alkyl.    An INDEPENDENT CLAIM is included for evaluation of flexibility of electrode. 2 parts mass Binder resin composition and water are kneaded, 100 parts mass active material is added, mixed, 5 parts mass conductive support agent is added and mixed, to obtain slurry for electrode. The obtained slurry is coated on electrical power collector, dried and electrode having electrode layer having film thickness of 20-200 mu m is formed on electrical power collector. The obtained electrode is cut out to 3 cm wide and 5 cm long, and set as test sample. The mandrel of diameter 5 mm is applied to the electrical power collector surface of obtained test sample, and one side of test sample is fixed on a tape. The state of electrode layer when a test sample is folded such that electrical power collector surface is inside the environment of 10% or less humidity, is observed, to evaluate flexibility of electrode. The electrode is positive electrode. The binder resin composition does not have change in electrode layer when the flexibility test for evaluation of the flexibility of electrode is performed.