The invention provides an agent for conferring resistance comprising a lectin as an effective component, which are able to confer resistance against external stimuli to animal cells, particularly mammalian cells, and to their cultured cells and various tissues in the living bodies. The agent for conferring resistance to external stimulus according to the invention can confer to such animal cells and/or tissues resistance against mechanical stimuli and/or proteolytic reactions, and thereby enhance graft fixation of the cells and/or tissues, as well as transplant tissues obtained by culturing them.