The scientific approach, or more generally said, is a scientific approach that is widely used in the process of learning science. To help students find concepts or principles in science learning activities, innovative and effective learning media were needed. One of the learning media that could be used was the Student Worksheet. This study aimed to determine the validity, practicality and effectiveness of LKPD based Discovery Learning in Aquatic plants Classification Material in SMP Class VII. The development procedure used a 4-D model which included the stages of defining, designing, developing and distributing. The study was conducted on class VII students at SMPN 3 Banyuasin I in odd semester 2018/2019. Data collection was done through 2 stages, namely non-test techniques (questionnaires and interviews) and test techniques (about the pretest and posttest). The data analysis technique in this study was quantitative descriptive analysis, which was used to present data from expert lecturer validation, student responses and student answers. The results showed that: 1) LKPD based Discovery Learning had good validation qualifications, based on the results of expert lecturer validation analysis; 2) LKPD based Discovery Learning was declared practical, based on the results of quantitative data analysis of student responses, suggestions and comments of students and teachers on the development trials and validation tests; and 3) the application of LKPD based on Discovery Learning in the classification of aquatic plants was said to be quite effective in improving student learning outcomes.