The thesis is of three objectives, namely:- 1) to study the belief in the scriptures of Theravada Buddhism, 2) to study the belief in the State Supporting The Method of reaching the aims in Theravada Buddhism,     3) to study the relationship of belief in the State Supporting The Method of reaching the aims in Theravada Buddhism. This research is conducted in the documentary terms. The data are collected from the Tipitaka as well as the commentary, the literature and the related documents, then are analyzed in the research principles and are presented in a descriptive study.

The research result meets that in Theravada Buddhism. Saddhā means the belief that has the intellect which sifts in making a decision. Saddhā means the belief in the Triple Gem which is connected with the achievement of the Dharma in Buddhism. Belief is of the characteristic of making the mind be clear and be without any trouble in Dharma achievement.  The causes to cause the belief in Saddhā to arise are the picture, the sorrow, the sound, and the dharma.  The belief is significant according to the meaning and the duty. It is basically the base in the procedure of developing it to the intellect, basically it is a base in the procedure of practising Kammaţţhāna which is the infrastructure in Dharma category. The belief is of 4 kinds, namely:- Kamma-saddhā, Vipāka-saddhā, Kammassakatā-saddhā, Tathāgatabodhi-saddhā. The values and the advantage of belief in human development are:- 1) The belief which causes the human being to receive the noble property. 2) The belief which causes the human being to go across Ogha. 3) The belief which causes the human being to attain the Dharma. 4) The belief which causes the householder to receive the present and future benefits.

The relation of belief in The state supporting the method of reaching the aim at the Lokiya level is the worldly wisdom. The belief arising form Ratanattaya and Yonisomanasikāra is the factor at occurrence at the Lokiya level. It is significant and advantageous to receive Lokiya-paññā.  Lokuttara-paññā is still valuable happiness in the present world and the nex one. The relation at the level of Lokiya is the initial factor of the practice according to Ariya-magga and the factor helping to Nivaraņa. When one develops the level to wisdom to the level of Lokuttara wisdom one will get Lokuttara-paññā. In order to have the knowledge of Lokuttara-Dharma, the monks should apply the three Sikkhās : Morality, Concentration and Wisdom to their practices. For the lay people, they should apply the three way of virtues:- Charity, Morality and Meditation of their practices. The relationship of belief at the Supramundane level is of the importance as the instrument in practicing Kammaţţhāna to attain the Path the Fruit and Nibbāna.