This thesis is of three objectives, namely:- 1. To study the origin and the importance of the counsellor in Theravāda Buddhist Scriptures, 2. To study the doctrinal principles for doing the duties by the counsellor in Theravāda Buddhist Scriptures, 3. To analyze the roles played by the counsellor in Theravāda Buddhist Scriptures. This thesis is carried out by the documentary research and by analyzation with the point.

From the research, it is found that the word “counsellor” means the person who is the adviser in the royal activities, the person who is the royal officers and the high ranking royal officers. The counsellor is the important person for the king and the one who helps the king in ruling and administrating the country. The king selected the counsellor from the person who is of ability and loves the country. The counsellor who is of the intention to do his duties with the honesty and the love can be in progress in his own duty, but the counsellor who has no intention to do his duty with honesty will be punished to be out of the position. Generally the counsellor is of the roles and the important duties on 5 sides and in doing the duties on 5 sides must be of the doctrinal principles to be used in doing the duty.

The 5 doctrinal principles to be used by the counsellor are:- 1. Rājavasatidhamma, Sappurissadhamma, Adhitthānadhamma and Lokadhammas all of which are used as the doctrinal principles which the counsellor used for giving the advice to the king. 2. Bāhusacca and Kalyāna-mittadhamma which are used for training and teaching the Dhamma to the king. 3. Kataññū,  Dasabidha-Rājadhamma, Aparihāniyadhamma and Brahmavihāradhamma are used for controlling the military and for administrating the country. 4. Agativiratti and Dhammādhipateyya are used in the judgment of the criminal cases. 5. Saṅgahavatthudhamma is used as the principle for helping the people, and Upasakadhamma, Puññakiriyavatthu and Ariyadhamma are also used as the principles in looking after the religious works. On the other hand, Gharāvāssadhammas, Apāyamukkhaviratti and Garāvāsasukha are used as the principles for looking after the families.

In the Theravāda Buddhist Scriptures, the counsellor is of the important roles and duties in the societies on 5 sides, namely:- 1. To give the advice to the king, 2. To give the knowledge of Dhamma to the king, 3. To control the military and to administer the country, 4. To judge the criminal case, 5. To manage the activities in the royal palace. These roles are of great effect to the political system, the administrative system, the economic system, the educational system and the social system. The said roles are brought to be used usefully and with the values to the present societies.