PURPOSE: To enhance water resistance of images, by a method wherein a water- base ink containing a water-soluble direct dye or the like is used for a recording material provided with a polyalkylene polyamine dicyandiamide ammonium salt condensate at least on a surface thereof.

CONSTITUTION: An aqueous solution of a polyalkylene polyamine dicyandiamide ammonium salt condensate is applied to a base paper by a size press, a roll coater, an other-type coater or the like to produce an ink jet recording sheet. Ink jet recording is conducted on the recording sheet by using a water-base ink containing a direct dye or an acid dye having an anionic free radical. By this, the dye contained in the ink and a cationic resin contained in the sheet are coupled with each other, whereby the dye is prevented from being eluted, and fastness stability against sun light enhanced. The content of the cationic condensate in the recording sheet is ordinarily 0.1W4g/m2.