The habitations Taiwanese government provided for those mental retarded people are no more than the three modes listed below: the home, the community, and the institution. However, in this kind of double-aging situation, the shortcoming of the design of these very modes of habitation is that the ”changed” and the ”unchanged” those advanced-aging mental retarded people and their parents experienced are not put into the consideration of the very design. In light of it, by taking the needs and the longings of the mental retarded children and their parents as the starting point, and through literary arrangement and review, this thesis will try to provide the possibility of another mode of habitation called the ”homeland for parent and child” through discursive formation. By the design of the new mode of habitation, this thesis will also hope to provide the physiological, the psychological and the social care for the double-aging families, in order for them to go through the last part of their lives in a ”well-settled”, ”peaceful”, and ”safe” way.