The purposes of the research were: 1) to study the level of ethical behavior of school administrators, 2) to study good characteristics of teachers, 3) to study the relationship between the ethical behavior of school administrators and good characteristics of teachers in schools under the Secondary Educational Service Area Office 18. The sample of this research were 385 administrators and teachers from schools under the Secondary Educational Service Area Office 18 in the academic year 2019. The research instrument was a three-part, five scale rating questionnaire regarding the ethical behavior of school administrators and good characteristics of teachers in schools under the Secondary Educational Service Area Office 18. Part 1 included the general information. Part 2 contained 53 items regarding the ethical behavior of school administrators, with a reliability of 0.60-1.00, a discrimination of 0.31-0.84 and reliability of 0.97. Part 3 consisted of 42 items about good characteristics of teachers with a validity of 0.80-1.00, a discrimination of 0.21-0.86 and a reliability of 0.96 and an overall reliability of 0.98. Data were analyzed by using Statistical Computer Program to calculate the percentage, mean, standard deviation, Pearson’s product-moment correlation coefficient and simple regression analysis