The objectives of this qualitative research were to study the role perception of subdistrict health supervisors, their supervisory performance to trained traditional birth attendants (TTBAs), the association between the role perception of subdistrict health supervisors and their supervisory performance to TTBAs and the needs and poinions of subdistric health supervisors and TTBAs concerning supervision Thae data were collected during May 14 to June 6, 1991 utilizing focus group discussion and indepth interviews, The samples were pupposive selected from one district in Sakolnakorn Province. There were 8 subdistrict health super isors and 38 TTBAs. The rusults of this study revealed that almost all subdistrict health supervisors had similar role perception in organizing, directing, controling, evaluating, reporting, counsellor, trainer, analyst advisor and motivating, but had some differecne role perception in planing, staffing, leadership and co - ordinating. The factors affected the subdistrict health supervisors role perception were their attitude, duration of being health personal, duration of being general supervisors and TTBAs suppervisors, receiving training to be TTBAs and community health workers trainer, recieving supervision from district and province, number and characteristic of job. The factors which did not affect the subdistrict health supercisors role perception were supporting for supercisory activities, number of village, population and TTBAs for theis responsibility, and their age. The subdistrict health supervisors role perception completely corresponded with the supervisory performance were organization and advisor, the role which partially corresponded were planing, staffing, directing, leadership, controling, evaluating, counsellor, trainer, analyst, motivating, and co-ordinating. The needs and opinions of subdistrict health supercisors concerning supervision were supercisory training, reducing workload, increasing number of health personal and budget. The needs and opinions of TTBAs concerning supervision were supervisory appointment, eyeglasses, identification card and reward. The similar needs and opinions of TTBAs and sudistrict health supercisors concerning supercisors characteristics were subdistrict health supercisors qualification and experiences in working at least 1 year, having good knowledge, ever being TTBAs trainer, having good communication, being polite, familiar and clam, supercising TTBAs every 3 months by home visit, supporting for supercisory activities, training new TBA or refreshing TTBA, every year. In addition, the poinions concerning TBA selected for training were a person who accepted by community. The recommendations emerging from the study are prociding an appropriate orientation or training program to the ones who will be TTBAs supercisors, providing periodical follow up and support from district and procincial health office, and improving the supercision system as stated by the needs of subdistrict health personals and TTBAs.