Cadmium (Cd) and copper (Cu) are types of heavy metals that can have an adverse effect on the ecosystem. Even copper is an essential metal but in limited concentrations, however, it leads to a toxic effect on the environment when used in high concentrations. Bioremediation of these metals can be done using microalgae Skeletonema costatum. In this study, bioremediation tests of Cd and Cu were carried out on a laboratory scale using various concentrations, control, 0.7, 1.3 and 1.9 ppm, respectively. The metals exposure was carried out for 96 hours. During the test the microalgae population was monitored, and the metal concentration in organism was calculated. The final analysis is to determine bioaccumulation factors as indicators of microalgae ability as heavy metals bioremediation-agent. Cd inhibits the growth of microalgae which is more than Cu. Yet, Cu is easily absorbed by Skeletonema costatum than Cd. The final analysis is to determine bioaccumulation factors as indicators of microalgae ability to be heavy metals bioremediation-agent in the bioconcentration factors (BCF) of Cd and Cu average are 6.15 and 7.97, respectively.