Abstract Waves is one of the Physics materials that must be mastered and understood. Students need help describing the mechanism of wave movement so it is necessary to develop a test instrument tailored to the scientific field of Biology. Therefore the study aimed to develop a Wave conceptual knowledge test instrument that can be used to train and measure the mastery of Physics concepts of the Wave topic of Biology Department students that meet the instrument s feasibility including content validity reliability and difficulty level. This research uses the 4D development model (Four-D models) which consists of four stages Define Design Development and Disseminate. Instruments-based feasibility is based on content validity test reliability and difficulty level. Based on the study results the instruments developed were based on indicators of achievement of Physics competencies for Biology Department students. The content was adjusted to the field of Biology namely the concept of waves in the human and animal hearing system. The test instrument met the criteria namely content validity test reliability and difficulty level so this instrument can be used to train and measure the physics concept mastery of Biology students. The wave topic adapted to the scientific field of Biology can help Biology students understand the wave concepts correctly. Keywords physics concept waves topic physics for biology knowledge test