This study attempted to find out the understanding of principals, teachers and students about quality of education in secondary school. Teachers believe that education quality in terms of input indicators with a total mean of (3.5) near to good. In terms of process indicators with a total mean value of (3.70) near to good. And in terms of output indicators with a total mean value of (3.4) that is fall to on average. As the result of this study indicated, students, teachers and principals perceived process factor of quality education especially student-centered factor below the average. In addition, the one way ANOVA result showed that there is a significant difference between the respondents of input and output factors. On the other hand, there is no significant difference between the respondents on process factors. As a whole they responded that input, process and out factor affect the quality of education.