This research determined priority of quality improvement of public institution's education service by using ASC for importance and applying Topsis, a multi-standard decision-making method simplifying various attributes and scales of evaluation items and deciding the comparative priority for satisfaction and discussed the differences so as to measure the quality of public institution's educational service and examine the priority of education service' quality improvement. This research classified the characteristics of quality improvement. As a result, it's significant to suggest positive direction and method to improve satisfaction and education service's quality from an angle of demander by analyzing educational satisfaction of education service quality of public education institution and effects on the following improvement.