The objectives of this research were: 1) to study the efficiency of the construction and renovation administration, 2) to study the factors associated with the efficiency of the construction and renovation administration, and 3) to study the problems, obstacles and develop effective methods to manage Sangha construction and renovation administration in Ayutthaya District, Ayutthaya Province.  Mixed researches i.e.  quantitative  and qualitative research were carried out in this study. The samples  in research consisted of 286 Sangha administrators in Ayutthaya District, Ayutthaya Province. The tools used for data collection were questionnaire and interview schedule. The statistical techniques used for data analysis were the frequency, percentage, mean, standard deviation, The data collected from key informants were analyzed by contents analysis technique.

The research results revealed that:

1. The overall efficiency of the construction and renovation administration of Sangha Administrators in Ayutthaya District , Ayutthaya Province was found at the high level (X = 3.77). When considered into each aspect, it  was also rated at the high levels in all aspects.

2. The analysis on the factors associated with the efficiency of construction and renovation administration of Sangha administrators in Ayutthaya district, Ayutthaya Province. It was found that there was significant relationship between leadership and the efficiency of construction and renovation administration of Sangha administrators in Ayutthaya district, Ayutthaya, at 0.001 level of confidence with correlation value (r) equal to 0.829.

3. The results of the interview the Sangha Administrators found that the individual factors of Sangha Administrators with age, rather than years of education or higher could manage more efficiently. While Sangha Administrators who were on duty directly could manage more efficiently than those who did not have responsibility in that job. In case of work efficiency, Sangha Administrators should have appropriate knowledge, vision, and morality in order to arrange efficiently. For the problem solving and methods, the administrators should be consistent with any circumstances in nowadays so they should have good consultant and qualified technicians. The administrator should build the unity in a team and the leader must be trained their mental stability, have faith on their work then all works will be accomplished efficiently.

4. The suggestions for the utility management of Sangha Administrators, problems and obstacles could be defined:

    1) In terms of efficiency, it should establish policies to guide operations, and cooperate in order to encourage work efficiency.

    2) The factors associated with the efficiency of public management should be operated by fairness and unbiased, devoting to the temples and Buddhism, investigating when there is mistake for making a judge to all administrators, considering the causes of the problems before solving in order to increase efficiency.