The purpose of development is to produce a valid instructional video media as a source of effective learning in science this topic of Calor in Seventh Grade class C. This research uses model of development Sadiman. Researchers chose Sadiman models because this model is designed to develop learning media such as audio, video and film. Besides the development model is a systematic and simple, so easy to be controlled at every step. The steps is, (1) Need assessment, (2) The formulation of objectives, (3) the formulation of the material, (4) the formulation gauges success, (5) scriptwriting media, (6) production, (7) trials, (8) the revision, and (9) media ready to use.