Non-curable refractory putty composition

Provided is a non-curable refractory putty composition which is lightweight and is excellent in terms of workability and fire resistance. The non-curable refractory putty composition comprises a filler, a binder resin, a hollow inorganic filler, and resinous microballoons, and is characterized in that the filler is selected from the group consisting of aluminum hydroxide, magnesium hydroxide, talc, and fly ash, the binder resin is selected from the group consisting of polybutene oils, liquid polybutadiene, liquid styrene/butadiene rubbers, liquid chloroprene rubbers, and liquid isoprene rubbers, at least some of the surface of the resinous microballoons has been coated with an inorganic powder, and the shells of the resinous microballoons are constituted of a resin selected from the group consisting of acrylonitrile resins, phenolic resins, and vinylidene chloride.