Abstract: In contemporary China，lineal families with three generations have been a typical family formation since the early 1980s. However，this trend differs between urban and rural areas. When children growing up in urban one-child families，especially after their marriage and childbearing，most of
them would not change their preference for a small family. In rural areas，the number of families with only one son has increased since the early 1980s. When growing up，most of those sons work outside the villages. Once getting married and bearing child，they need help from their parents for housework
and childcare. Since such family arrangement is beneficial to young people，its proportion has increased. The majority of the householders of lineal families with three generations were in the middle and early old age in 2010 and their family function of supporting elderly has been weakened. More than half of the lineal families with three generations have no members aged 65 and above in 2010. At the same time，the infant proportion of the lineal families with three generations has gradually increased since the early 1980s. The function of taking care of children has been enhanced in this kind of family.

Keywords: Lineal Family with Three Generations, Family Function, Census Data

摘要： 当代中国三代直系家庭构成既有总体稳定的一面，也表现出城乡变动趋向具有差异的另一面。城乡三代直系家庭变动具有差异的原因在于，城市独生子女长大之后，特别是结婚、生育后，并没有改变对小家庭居住方式的偏好; 而农村家庭独子增多，长大后外出非农就业成为主流，结婚、生育后与父母同居共爨“获益”较多，且矛盾冲突少于多子家庭，三代直系家庭比例因此提高。2010 年城乡三代直系家庭户主构成均以中年和低龄老年人为主，此类家庭的养老功能有所削弱，2010年一半及以上的三代直系家庭没有65 岁及以上老年人; 婴幼儿在其中生活的比例呈现增长趋向，中年和低龄老年人于这一家庭内帮助子代“抚幼”，提升了其助子育幼的功能。

关键词: 三代直系家庭, 家庭功能, 人口普查数据