Family structure is the way that a household or a family is set up. Usually, there are 4 typical types of family structure: extended family(parents, children and several relatives), nuclear family(a father, mother and children), single parent family(one parent with at least one child), and childless family(a husband and wife). Currently, family structures mentioned above all exist in China, along with some other specail family structures like stepfamily and grandparents family. Among these family modes, the extended one keeps its key role in the forming of families in urban China while the nuclear one is playing an increasingly significant role. Nevertheless, constantly affected by some political, economic and cultural factors, the chief family structure in urban China is experiencing a change from extended family to nuclear family.