This manuscript was written in order to study the traces of filial duty in the late period of Silla through Sonsoon : attempt to bury a child and A Poor Daughter and Mother, which are contained in the chapter of filial piety and virtue in Memorabilia of the Three Kingdoms. In the story, Sonsoon : attempt to bury a child, poor parents tried to bury their child for the father’s mother, however, they found a stone bell, King Heungduck, who hears the ringing sound of the bell, called Sonsoon upon him and awarded Sonsoon for his filial duty. After, he contributed his old house and built Honhyo Buddhist Temple. Sonsoon’s way of filial duty is sacrificing one’s child only for one’s parents, which is Buddhistic way. The reward from King Heungduck contributed Sonsoon to build Honhyo Temple, and the name of the temple, Honhyo, was also named by the king. Through Honhyo Temple, which means promulgating filial duty, we can figure out that the king aimed to boost the loyalty to the Kingdom. In the story, A Poor Daughter and Mother, a woman, who lives as a beggar, supported her mother by selling a part of her body, but she realized her action was not what her mother wanted and meditates the true meaning of filial duty. Not only the daughter and mother appears but also Hyojongrang stands out in the story. Starting with Hyojongrang’s reward for the filial duty of the daughter, even King Jinseong commended and rewarded her. The story of the poor daughter caused Hyojongrang to stand out politically and was used for King Jinseong to stablize his stand politically. The poor daughter, after the commendation and the reward, contributed her rewarded house to built Yangjon Buddhist Temple. The name Yangjon was named by Hyojong, meaning up-rearing the king and parents as high as Buddha. The background of these two stories is just same, the ways of filial duty and reward/commendation are not the same. Though, the stories received attention because the results of both filial duties end up with Buddhist services. Honhyo Buddhist Temple and Yangjon Buddhist Temple are instances which appear after prohibition of Buddhist service of King Aejang, especially, they are built by people of upper class. They were not built in the reason of political method nor concealment for wealth. Their reasons of contributing the houses seemed just for living. The filial duty in the late period achieves stabilization of reality through the filial duty and also pursues stabilization of afterlife. The filial duty is very fundamental action in a family. Using the concept of the duty for loyalty and national ruling ideology was appeared in every corner of Silla. In the late period, the category of the duty shrank and ways changed dramatically extreme, but still the country utilized the filial duty in order to stabilize public sentiment. Also, through building Honhyo and Yanjon Buddhist temple, as the country reached the late period, it is thought that the filial duty was not only in consideration for the reality but also aiming to the afterlife.