This thesis consists of three objectives, namely:- 1) to study Phra Uruvelakassapa’s biography;  2) to study Phra Uruvelakassapa’s roles in the propagation of Buddhism; 3) to analytically study his roles  in the propagation of  Buddhism.

              From the research study, it is found that in his past biography, he used to wish to be in the highest position on the side of having the most retinues among the Phra Padumuttara’s disciples at Phra Padumuttara Buddha’s time. Later, in his last birth, he was born in Brahmaṇa Caste in Barānasī city. When he had grown up, he completed his study in Tiveda (Three Vedas). After his completion of studying the three Vedas, he was bored with the lay life. Thus, he was ordained with 1,000 retinues and went away from the lay lives and finally all of them became the ascetics. Later, he listened to the Gotama Buddha’s teaching, attained the Enlightenment and became Arahanta. Thus, the Buddha had more disciples quickly. Thus, he was appointed by the Buddha to be the highest person in the matter of having most retinues.

     Phra Uruvelakassapa had the important roles to propagate Buddhism, such as the roles in the propagation of Buddhism associated with many persons and the roles in the propagation of Buddhism related to the Buddha’s principles consisting of the teacher’s qualities, the aim in teaching, the method of teaching, and the technique in the propagation of Buddhism in causing  people and his retinues to have belief in  Buddhism and he also had significant roles  in the propagation of Buddhism at later time.