Rubber seeds (Hevea brasiliensis) are part of rubber plants that have not been utilized optimaly. The content contained in rubber seeds is sufficient, including fat content of 68.53 g/100 g, proteins 17.41 g/100 g, and carbohydratees 6.99 g/100 g. However, the obstacle faced is the presence of toxic compounds found in rubber seeds namely cyanide acid (HCN) which is very dangerous if it enters the body. The purpose of this study is to find out the right treatment to reduce the content of cyanide acid so that the rubber seeds can be utilized. The research method uses experimental comparative. The variation used in the reduction process is to soak the rubber seeds respectively for 12, 24, and 36 hours by replacing the immersion water once ever...