Provided are the use of poly(N-isopropylacrylamide-co-butyl methacrylate) in preparing an embolism material for blood vessels, an embolism material for blood vessels and the use thereof in preparation of drugs. The embolism material for blood vessels comprises poly(N-isopropylacrylamide-co-butyl methacrylate) and a dispersion medium consisting of an electrolyte, a contrast agent, a pH regulator and water. The concentrations of the polymer, electrolyte and contrast agent are respectively 5-30 mg/ml, 0.1-30 mg/ml and 100-350 mg/ml based on iodine. The embolism material for blood vessels is suitable for embolization therapy of tumors in hypervascular and parenchymal visceral organs.