Objective: The influence of depression, anxiety, and family function in breast cancer patients on the quality of life of their children was investigated from the perspective of the participants’ demographic characteristics after controlling for their attributes. Methods: The demographic characteristics and confounding factors were divided into two subgroups, and two-factor analysis of variance was conducted with depression, anxiety, and family function as the independent variables, and the children’s quality of life scores as the dependent variable. Results: The quality of life of children in each characteristic demographic-subgroup was significantly lower when their mother had high depressed. Moreover, the quality of life in children of the subgroup with mothers receiving chemotherapy varied according to the quality of family function regardless of having siblings. Conclusion: It is necessary to focus on the conditions of children in addition to the psychological status of breast cancer patients. This investigation suggested that understanding mothers’ psychological status helps to identify children’s psychosocial problems. Moreover, it is suggested that the demographic characteristics of families with breast cancer patients should be considered when approaching mothers’ psychological status and family function.