A content learning system based on discovery learning is an electronic learning process using web learning and combining discovery learning models. The purpose of this study was to develop a discovery learning-based content learning system on the atomic structure and periodic system of class X SMK to improve students' practical thinking skills. This research model uses the ADDIE development model. This research is limited to the implementation stage, which is to see the practicality of a discovery learningbased content learning system that is tested on a limited basis. Based on the practicality test results of the discovery learning-based content learning system by going through two assessment data, namely the first teacher response questionnaire data with an average value of k is 0.89 very high categories, and secondly, the student response questionnaire data with an average value of k is 0.88 very good category. It was concluded that the content learning system based on discovery learning on the material of the atomic structure and the periodic system of the elements produced was said to be practical.

Keywords : Practicality, Content Learning System, Discovery Learning, Atomic Structure And Periodic System Of Elements, Higher-Order Thinking Skills