The objectives of the study were as follows : 1) to study the context of the Four Brahmavihara of Institution Administrators in Nakhonsawan Municipal Schools 2) to compare the opinion of municipal teachers towards the administration in according to Four Brahmarihara of Institution Administrators by classifying on the personal factors, and 3) to study the ways of administration and suggestions to the Four Brahmavihara of Institution Administrators in Nakhonsawan Municipal Schools. Research using the population which was taken from 349 municipal teachers including 8 schools.

The research method used by Survey Research. The sample was drawn for 183 people. The tool used questionnaires with have been created initially by the researcher. The five experts were selected as the content validity checking. The data were analyzed with statistical approach to find frequency, percentage, mean and standard deviation. the test of hypotheses were applied t-test, F-test (One Way ANOVA) and least Significant Difference : LSD. And summarize the ideas and suggestions were as follows.  

The findings of the study found that most of municipal schools teachers were males for the number of 92 with equivalent to 50.30%. When considering to age, most of the respondences had 31 – 40 years old for the number of 96 with equivalent to 52.50%. Moreover the respondences graduated in bachelor’s degree for 92 people with equivalent to 50.30%. Referring to working experiences ; most of them had working experiences during 1 – 5 years for 102 people with equivalent to 55.70%. The sample was drawn from the large school size which consisted of 126 people with equivalent to 68.90%. The opinion of administration according to the Four Brahmavihara of Institution Administrators in Nakhonsawan Municipal Schools were in high level (= 4.05) as a whole. Furthermore in every aspects of Brahmavihara : Metta (loving - kindness), Karuna (compassion), Mudita (sympathetic) and Upekkha (equanimity) were in high level in all aspects. The municipal teachers had the opinions towards Education Administration according .On the descending order of means it were found that Mudita and Upekkha were in high level (= 4.12). The lower mean scores were Karuna in high level         (= 4.03) and Metta in high level (= 3.94). the comparison of the opinions of the administration in according to the Four Brahmavihara of Institution Administrators in Nakhonsawan Municipal Schools by classifying on personal factors ; the test of hypotheses were found that no significant differences. The hypotheses of the study have been rejected by gender, age, educational level and school size for significant differences at .05 level. The only hypothesis which has been accepted was working experiences with significant difference at .05 level. The respondences who have been working experiences between 1 – 5 years indicated lower mean scores than the group of   11 – 15 working experiences years with significant difference at .05 level. The respondences who have been working experience for 11 – 15 years expressed higher mean scores than the group of 16 years and above with significant difference at .05 level.