This study explores the relationships among the filial beliefs of middle-aged and elderly people, perceived filial behavior of their daughters-in-law, and their own depression and happiness. This research adopted a self-reported questionnaire survey method. The valid sample size is 233 with 50-69 years old middle-aged and elderly people. The research measures include the "Chinese happiness scale (very short version)", "TLSA short CES-D mental depression scale", "dual filial piety scale" and "perceived daughter-in-law's filial behavior scale" adapted from "dual filial piety scale". The statistical methods of data analyses include Pearson's correlation, independent sample t-test, and multiple regression analysis by controlling for demongraphic variables. The main findings of this study are shown as follows： (1) Middle-aged and elderly people still generally value filial piety (no matter reciprocal or authoritarian filial piety), and the importance of reciprocal filial piety is still significantly higher than that of authortarian filial piety. The authortarian filial piety beliefs of middle-aged and elderly people are positively correlated with their sense of depression; The reciprocal filial piety beliefs are positively correlated with their sense of happiness. (2) The more middle-aged and elderly people (in-laws) perceive the reciprocal and authortarian filial behavior of their daughter-in-law, the lower their sense of depression and the higher their sense of happiness. (3) The scores on authortarian filial beliefs are significantly higher for those who are older, have not received higher education, and live with the designated daughter-in-law; at present, those who have children living with them, and have the designated daughter-in-law living with them have significantly higher scores on perceived daughter-in-law's dual filial behavior; those with poor self-assessed physical health had a significantly higher score on depression and a significantly lower score on happiness. (4) The two kinds of filial behavior (reciprocal and authoritarian) enacted from their daughter-in-law perceived by middle-aged and elderly people (in-laws) can help their personal psychological adaptation. On the one hand, they can increase their happiness, and on the other hand, they can reduce their depression. (5) The moderating effect of the authortarian filial belief of the middle-aged and elderly people in each mentioned model has reached a significant level; this result implys that authoritarian filial belief plays an important role of the interaction between Taiwanes parents-in-laws and daughters-in-laws. The results of this study can be used as a reference for the interaction between the parents-in-laws and the daughters-in-laws.
