The identity development resulting from caring for an important object has attracted considerable attention in recent times. Mothers having children with severe motor and intellectual disabilities were analyzed from the perspective of differences in identity crisis-, development, and the process of identity development. Semi-structured interviews were conducted with 15 participating mothers having children with severe motor and intellectual disabilities. The date obtained on personality development of mothers were classified into six categories: "deep understanding of human relationships", "acquiring new behaviors", "extended self-sensations", "deep understanding of the meaning of life", and "acceptance of own death". Four types were classified according to differences in identity crisis and development. Results were suggestive of a connection between identity development of mothers and the qualitative aspects of the mother-child relationship.