Abstract: An investigation of the concept of marriage and childbirth in Yu Village of Zhejiang Province over the past 40 years finds that the change from the conventional normative concept of "having children after marriage" to the wide acceptance of "having children before marriage" can be explained as a trade-off strategy against the one-child policy to secure the continuity of family name. When the One Child policy ended, some families in the village once again adhered to the norm of having children after marriage. However, with the skyrocketed cost of marriage involving in luxury weddings and new houses, "having children before marriage" came back in fashion again in the village since 2010. Judging from the number of children born before marriage in the village, it seems that the traditional concept of having children after marriage has almost been abandoned. Nevertheless, if one examines the structure of meaning behind the now much expanded engagement ceremony, one can see it essentially redefines the "witness" and "acknowledgement" for marriage and childbearing. The elaborated engagement ceremony helps coping with the moral crisis of childbirth before marriage. In so doing, people adjust the concept structure to suit different situations and reconstruct the norms so as to carry on the spirit of certain tradition. This reflects the old saying of "changing in constant and constant in changing." Therefore, the discussion of concept change should not be simply based on a particular segment, or a phenomenon, or a form. Instead, one needs to look at the whole landscape, mechanism, and substance of concept change. It is necessary not only to grasp the "mutation" mechanism of tradition but also to truly appreciate the continuity behind the change, so as to reach a more fundamental understanding of the social structure in connection between tradition and the present.

Key words: having children before marriage, concept structure, ritual, transformation