PURPOSE: To provide the titled compsn. which can be crosslinked or polymerized by irradiation with a radiation, contains magnetic particles well dispersed therein and gives a coating film having excellent smoothness and durability, containing a binder contg. nitrocellulose having radiation-sensitive unsaturated double bonds and a magnetic powder as main components.

CONSTITUTION: The titled magnetic paint compsn. contains a magnetic powder and a binder as main components. A binder contg. nitrocellulose having radiation-sensitive unsaturated double bonds is used. Examples thereof are nitrocellulose having maleic, allylic or acrylic double bonds. Examples of the radiations are electromagnetic waves having a wavelength of 3mm or below such as infrared rays, visible light and electron beams. Examples of the magnetic powders are ferromagnetic iron oxide powder, ferromagnetic chromium dioxide powder and ferromagnetic alloy powder.