This paper tries to ascertain the state of the art in family theory and to identify the discussions and topics which contributed to progress in the field. For this purpose, the most influential approaches in German family sociology are discussed, followed by two sections focusing on the relationship between family and society, and the internal structure of the family, respectively. One result is that the problems of theoretical integration are increasing because some of the research fields that were formerly part of family sociology now have abandoned the field. An integrated theory of the family, however, seems to be an important issue for the future when regarding the challenge of family research by the success of biology and life-sciences.