Microplastics (MPs) had become a major concern in pollution studies due to its significantly increased amount in the worldwide. The effect of larger size microplastics had been proven in numerous studies which can be fatal when consumed. However, the effect of smaller size plastics such as microplastics in living organism is still not widely studied. The aim of this project is to understand and reveal the effects of microplastics on Javanese medaka, a model organism in aquatic environment. We conducted transcriptomic analysis on fish exposed to 1 micrometer MPs for seven days. The RNA of the fish liver were extracted and RNA sequencing was performed.