A deinking agent comprises a compound of the following formula (I);N(R.sup.1)(R.sup.1) R.sup.2 (I)wherein R.sup.1 is --C(O)R.sup.4 or --(C.sub.2 H.sub.4 O)C(O)R.sup.4 ; R.sup.2 is --(C.sub.2 H.sub.4 O)--(AO).sub.m or --(AO).sub.m ; R.sup.3 is --C(O)R.sup.4 or --(C.sub.2 H.sub.4 O)C(O)R.sup.4 ; R.sup.4 is C.sub.9-23 alkyl or C.sub.9-23 alkenyl; m is a integer from 40 to 100 and A is C.sub.2-4 alkylene, and a quaternary ammonium compound thereof in a molar ratio of 9/1 to 1/9. The deinking agent for reclaiming printed waste paper has abilities to efficiently release the ink from the waste paper in the disintegration process and to collect the ink and produce suitable foam in the flotation process, which provides high quality reclaimed pulp having high whiteness and a low content of remaining ink.