The elevation of present medical service using advanced science contributes to offer medical examination and treatment of good quality under the subject of patient satisfaction as well as patient impression. The dental service field charging some part of public health promotion and public welfare promotion also intends to improve the dental examination and treatment quality utilizing advanced science. The object of this research is the development of dental treatment assisted system (DTAS) using multimedia technology. DTAS can be employed for these object ; harmonious operation of dental examination and treatment, treatment quality improvement, disease notice to patient under the subject of patient satisfaction and patient impression, explanation of some selective treatment course, the verification of treatment necessities and treatment validation, and the improvement of treatment effect through the oral hygiene education in the sense of prevention. This research also serves the development environment, the step to collect educational document, visual information and to structure those, and the examination of DTAS efficiency in clinic.