The objectives of this research were to: 1) development of an appropriate learning management system for primary schools via the LINE application 2) find out the efficiency of an appropriate learning management system for primary schools via the LINE application, and 3) study the user’s satisfaction when using an appropriate learning management system for primary schools via the LINE application. The sample group consisted of 40 users divided into 15 teachers and 25 students in Anubanphana (Udomwittayakorn) School, Phana District, Amnat Charoen Province, and was selected through purposive sampling, The research tools included: 1) An appropriate learning management system for primary schools via the LINE application. The development of a system utilizing the System Development Life Cycle and computer programming languages; PHP, HTML, and JavaScript, for webpage creation and user interface design. MySQL is a database management system, with Linux CentOS as the server operating system, Apache as the web server, and Google Chrome as the web browser. Developed by technology: Line application, Line developer account, and Webhook. 2) Efficiency evaluation, assessed by five experts in information technology development using black-box testing techniques. 3) Satisfaction survey on a Likert scale and statistical methods used for data analysis, including mean and standard deviation.

           The research findings were as follows: an appropriate learning management system for primary schools via the LINE application can be applied in the actual teaching and learning process, allowing learners to access content anywhere, anytime. The evaluation of system performance was found to be at a high level (= 4.46, S.D.=0.50), teachers’ group user satisfaction was also at a high level (= 4.49, S.D. =0.50). while students’ group user satisfaction was also at a high level (= 4.34, S.D. =0.50).