The Ministry of Public Health’s constant formulation of primary health care policy and carry forward to Primary Care Act 2019 in order to develop Primary Care Cluster (PCC) system and primary care network in addressing healthcare access problem and medical care gap, supporting the primary health care workers are able to collaborate with Family Medicine in order to improve the services quality. Primary colleges under Praboromarajchanok Institute Act play an important role in strengthening personnel to support primary care cluster team and perform quality works. This mixed-method research aims to 1) examine the situation of public health personnel development to support Primary Care Cluster (PCC) team; 2) study public health personnel’s competencies in supporting Primary Care Cluster (PCC) team; 3) explore competencies of lecturers under Praboromarajchanok Institute in public health personnel development to support Primary Care Cluster (PCC) team; 4) analyze Praboromarajchanok Institute Act in light of strengthening of public health personnel to support Primary Care Cluster (PCC) team; and 5) synthesize policy proposals to develop the role of colleges under Praboromarajchanok Institute Act in strengthening health personnel to support primary care cluster team. The research method was used a mixed method design. Both qualitative and quantitative data are gathered in this study. The data were collected within 12 months between August 2010 and July 2020. The in-depth interviews and focus group were used to collect qualitative data. The key informant includes the Ministry of Public Health’s senior experts in charge of manpower and primary care service and network, primary care system division directors, provincial public health officers and heads of related sections in provincial public health offices, directors and deputy directors of colleges under Praboromarajchanok Institute, Ministry of Public Health, lecturers in charge of academic services or personnel development of Colleges of Nursing and College of Public Health under Praboromarajchanok Institute, Ministry of Public Health, primary operation personnel for supporting the policy on Primary Care Cluster (PCC) team and general residents and public as well as services recipient. The sample The quantitative and qualitative data are analyzed using descriptive statistics and content analysis, respectively. The following research resultsare found: 1. All colleges are prepared for operations according to the roles and missions of respective colleges and Professionals Council in the fulfillment of higher education standards of the Office of Higher Education Commission. Meanwhile, public health personnel development is executed according to Praboromarajchanok Institute’s policy or to the needs of local area or Area Health to support the service plan such as emergency practitioner nurse curriculum, critical care nursing curriculum and palliatives care curriculum. Also, the training program is arranged in response to the country’s demand such as “Thailand’s increasing number of elderly leads to the introduction of elderly-related curriculum” or to the expertise of lecturers in respective colleges e.g. family practice training program and cancer nursing curriculum. The training plans are in line with future needs of healthcare, while the colleges develop the lecturers’ expertise in each discipline in accordance with curriculum formulation as required by Area Health or with problems in local areas. Moreover, training programs that derive from university’s needs in uninterruptedly promoting expertise are also performed in collaboration with other agencies. 2. Staffs in Primary Care Cluster (PCC) team have a high level of overall picture of opinions towards all aspects of competency of public health personnel to support Primary Care Cluster (PCC) team. In particular, the ones with the highest and lowest mean scores are ‘good service’ (Mean=4.18, SD=.79) and ‘accumulated work expertise’, respectively.( Mean=3.83, SD=.97) 3. There is a high level of overall picture of competency of lecturers under Praboromarajchanok Institute in developing public health personnel to support the policy on Primary Care Cluster (PCC) team. When each competency is examined, most competencies are found at a high level, except the knowledge and understanding of Primary Care Cluster (PCC) principle, which is at a moderate level. (Mean=3.58, SD=.93) 4. Regarding the production and development of primary health care personnel by Colleges of Nursing under Praboromarajchanok Institute Act, the understandings and competencies of lecturers should be promoted in order to jointly introduce nursing curriculum for other agencies, which collaborate with health services or the Faculty of Nursing overseas. Besides, the primary health personnel development includes the introduction of specialized curriculum, extended from the curriculums of nursing practice and of family practice. The participation and learning in collaboration with the relevant communities is also created. 5. The research results indicate that the guidelines for development of roles of colleges under Praboromarajchanok Institute to support the primary care cluster team’s operations can be done as follows: 1) improvement of nursing curriculum or adjustment of instructional activities integrated with primary care systems to enhance the graduates’ post-graduation work ability; 2) survey of needs for development of public health personnel’s competencies in operating primary care cluster team and primary care system at both national and health canter level; 3) arrangement of training programs related to primary care covering all multidiscipline of Primary Care Cluster (PCC) team according to the local area’s needs; 4) formulation of long-term academic service plans and of colleges’ clear administration guidelines for public health personnel competency development; 5) development of an apparent plan for lecturer-related manpower development and of lecturers’ competencies in promoting knowledge and ability of nursing students to perform quality primary care services. This is to facilitate public health personnel competency development to support primary care cluster team’s operations; 6) building of network collaboration in developing a center of expertise or excellence that meets standards to support primary care cluster team’s operations; and 7) development of inclusive manpower information management system, especially lecturers under Praboromarajchanok Institute, for decision-making purpose in light of number, qualification, expertise and distribution according to Area Health.