The Use of Interactive Multimedia for Increasing Concept Mastery, Critical Thinking, and Retention of the Human Reproductive System Concept at Senior High School Students Ipin Aripin 1 1 Program Studi Pendidikan Biologi, Universitas Majalengka Jl. KH. Abdul Halim No. 103 Majalengka 45418, Indonesia a) E-mail: i.arifin85@gmail.com Abstract. The aims of this study were to examine the effectiveness of the use of Interactive Multimedia in improving the mastery of concept, critical thinking, and student retention on the concept of human reproduction system. The research design in this study was "pre test-post- test control group design" with sampling technique of cluster random sampling, involving 82 students of class XI IPA. The data collected was the mastery of concepts, critical thinking, and retention on the concept of the human reproductive system that use dynamic multimedia and static multimedia. Instruments include objective test questions, questionnaires, observations, and interviews. The Z test results and the Mann-Whitney test at α = 0.05 indicated a significant difference in mastery of student concept with N-gain 0.50 in dynamic multimedia class and N- gain 0.34 in static multimedia class. The students' critical thinking skills improved with N-gain of 0.51 in dynamic multimedia class and 0.21 N-gain in static multimedia class. There was no significant difference in retention of learners with dynamic multimedia and static multimedia. The results of the questionnaire show that multimedia-assisted learning is favoured by students. Observation analysis of dynamic classroom in learning activities was more active in learning than static multimedia. Some of the obstacles encountered in computer-based learning include: the limited number, the completeness of computers available in schools, the skills of teachers and students using computers, as well as software resilience. 1. Introduction The learning process is an interaction between the components of education. According [1] the main components are; 1) students; 2) content / subject matter; and 3) teachers. In the interaction between these components required facilities, infrastructure and environmental arrangement so that the learning process can achieve the learning objectives that have been determined. One of the teacher's duties is to deliver the subject matter to the students. Even though, [2] states that the task of teachers not only deliver the knowledge but he must be able to transform to the children in order to they able to think integral and comprehensive, to form the competence and achievement of the highest meanings. Good teachers play a role in providing, showing, guiding, and motivating the students to interact with the various learning resources [3]. The success of teachers in delivery of the material is very dependent on the smooth interaction between teachers and their students. To overcome the limitations in the interaction requires an intermediary / media. Computer-based or known as multimedia is a type of media that combines text, sound impressions, vocals, music, animation and video with interactive software [4], [5].