Reconstructing the concept of family can better respond to the challenges posed by low fertility and the transitional society in this era. The article traces the formation and evolution logic of the concept of family, reviews the efforts made by the academic community so far to reconstruct the concept, and puts forward the redefined concept. The concept of “family” in China was formed through a hybrid system and ideological framework that emerged from the dual logic of the “family” in the patriarchal system and the “household” in governance, and was shaped by the transplantation of modern concepts and the changes in contemporary society. The evolution of the Western concept of family provides a necessary historical reference for understanding the institutional dependence and cultural adaptation issues of the concept of family generally used in China. The academic community both at home and abroad are reconfiguring the family in terms of theory, methods, and policy adjustments, with focus shifting from “household” to “kinship”. The article redefines the concept of family as: “A network of resource sharing and risk allocation formed by individuals connected through kinship and quasi-kinship relationships such as marriage, blood ties, or adoption”, which can be illustrated as a nested circle that expands from the inside out, consisting of “household-shared family—functional family—kinship circle family”.

Focusing on the phenomenon that childbearing-age people "do not want to give birth, ""dare not to give birth," and "are unable to give birth," we comprehensively consider the three dimensions of fertility—intention, conditions, and structure, build a fertility composite index according to the relevant theories of low fertility rate, observe and analyze the current situation of low fertility rate in China, and make inter-provincial comparisons. We find that the average national fertility composite index is 0.492. The fertility condition index is the lowest, reflecting the constraints on fertility caused by employment and income factors and lack of fertility support. The structural characteristics of the childbearing-age people are consistent in all provinces, while the fertility intention and fertility conditions are spatially heterogeneous. There is a positive association between fertility index and total fertility rate. With a 0.1 unit increase in fertility index, total fertility rate increases by 0.286 units. Improving fertility intention can help effectively increase the total fertility rate; however, the changes in fertility conditions and fertility structure have not been able to effectively promote the total fertility rate. It is thus necessary to establish, improve, and implement long-term fertility support in order to reshape the fertility intention and change the behavior of the population.

The deviation between fertility desires and behaviors is common among Chinese people of childbearing age. Little attention has been paid to the satisfaction of fertility desires from gender and time dimensions and its determinants. Based on data from the 2021 national sample survey conducted by the Center for Population and Development Studies of Renmin University of China, this paper analyzes the satisfaction of fertility desires and the effect of family characteristics from three dimensions. The results show that more than half of the couples of childbearing age want to have children but failed to meet their desired number; forty percent failed to satisfy the desired sex; more than eighty percent did not meet the desired time with a later age of childbearing than the desired timing. The socioeconomic status and fertility potential of family play an important role in satisfying the desired number for all the couples. The effect of family fertility culture is not significant. The couples with unsatisfied sex preference tend to have more children to fulfill it. It is suggested to make precise policies for different types of couples of childbearing age to help them meet their fertility desires.