A paper transparentizing agent, containing at least one amide compound selected from the group consisting of: an amide compound (A) that results from condensation of a monocarboxylic acid and at least one amine compound selected from the group consisting of polyalkylenepolyamines and alkanolamines; an amide compound (B) that results from condensation of at least one monocarboxylic acid, at least one polycarboxylic acid and at least one amine compound selected from the group consisting of polyalkylenepolyamines and alkanolamines; an amide compound (C) that results from condensation of a condensate and a monocarboxylic acid, the condensate resulted from condensation of at least one amine compound selected from the group consisting of polyalkylenepolyamines and alkanolamines, and epichlorohydrin or urea; and an amide compound (D) that results from condensation of a condensate, at least one monocarboxylic acid and at least one polycarboxylic acid, the condensate resulted from condensation of at least one amine compound selected from the group consisting of polyalkylenepolyamines and alkanolamines, and epichlorohydrin or urea.