The purpose of the present invention is to create an immune tolerance-inducing agent used in therapy in which donor hematopoietic cells are transplanted into a recipient in order to induce immune tolerance in the recipient with respect to donor cells, tissue, or organs. By using an alpha-galactosylceramide-containing liposome in combination with a costimulatory-pathway-blocking substance, hematopoietic chimerism can be induced in the recipient by transplantation of donor hematopoietic cells, making it possible to induce immune tolerance in the recipient with respect to donor cells, tissue, or organs.