This study started from a theory that children should read fables to develop a sense of morality. Many scholars have argued that the first and second grades elementary school students belong to the age of fable, and they are required to read fables. That argument coincides with the Piaget's moral development, where children aged 8-9 moves from the heteronomous morality to autonomous morality, and at that time they need moral standards or moral grounds. This study aims to examine such argument is true, especially the first and second grade students in elementary school as many scholars have said. For the aim, the study compares the morality level of students of first and second grade in elementary school and the morality level of Aesop fables by using Kohlberg's moral development. In addition, it tries to find out fables include moral values that are essential to develop children's morality, and it compiles fables that are not suitable for children in terms of contents or subjects. If the study proves that fables are suitable for children in terms of moral level and appropriate subjects, it will move forward to find out how fables are applied in the class environment. Especially, it uses a fable with moral conflict and finds out it is really efficient in developing morality as Kohlberg said. Findings of the study are as followings: First, the study matched 448 Aesop fables to the Kohlberg's morality development, and found that fables in the first stage are 158 (35.5%), followed by ones in the second, third, fourth, and fifth stage being 148 (33%), 13 (2.9%), 10 (2.2%), and 9 (2%), respectively. Fables in the first and second stages take up 68.3 percent, representing that fables are suitable for children in the first- and second- grade students in elementary school to develop their morality. Second, the study found that the most frequent subject is warning against foolishness (42), followed by greed and vanity (37), wisdom (29), origin and history (28), understanding and consideration (22), warning against lying and cheating (9), arrogance and self-conceit (16), and being hoisted on his/her own petard (11). In addition to them,many moral values that the 7th Curriculum emphasizes are shown: respect to life, integrity, honesty, temperance, respect to the elder, cooperation, compliance, justice, etc. However, the study found 44 out of 448 Aesop fables are not suitable for children, accounting for 9 percent. Overall, most of Aesop fables are found to have stories that are suitable for developing children's morality. Based on the result, a discussion class was planned. 4 of second grade students were selected and they were asked to listen to a fable about moral conflict. They were monitored in order to find out they may develop a sense of morality. The observation showed that children could not resolve conflicts with their lower level of morality and they were required to use and develop higher level of morality. These positive findings suggest that this instruction method can be applied to reading class as well as small-and large- classroom activities. Further, I want to examine teaching methods and texts that can change affective and behavioral aspects of children as well as cognitive ones in the future.