Gratitude is the source of all the virtues and contains universal value. Recent studies in positive psychology has proved that gratitude is not only a personal mental quality, but also an important element of being happy. Gratitude is best to be shape for children at the age of 6-12-yearsold, especially through learning gratitude courses. Researches also confirm that acquiring the feeling of gratitude can heal common characters of being spoiled among children of this period of time. The healing is certainly an assurance for them to live later on in their life in well-being. Hence, learning gratitude is a worthwhile practice in one's life. This paper discusses the meaning of gratitude from many points of view including philosophy, culture, religion, and psychology in order to reach a distinct view. Then the paper will further take ideas from theories of moral emotion, cognitive emotion, and the broaden-and-build theory to expand the construction of the idea of gratitude. After confirming values of gratitude, it suggests some methods to exercise gratitude in daily life which is referred to by educators in their teachings.