The crimes against humanity, a disaster of the 20th century and the present time, has given rise to the terrible human tragedies in the human societies. To find some vital strategies to prevent such crimes is a must since the high number of the victims and the casualties of these crimes are considered a great threat to the international peace and security. Reaching a comprehensive plan in order to prevent these highly complex nature crimes requires seems to be impossible. However, this fact should not stop us from attempting to reach necessary strategies to prevent such crimes. These strategies are studied from two perspectives: penal and non-penal one. In the non- penal approach, according to the common and classical criminological classification, social and situational issues will be analyzed here in. The penal prevention which is materialized through punishing criminals against humanity can play an important part in this respect by neutralizing the thought of not punishing the criminals as a factor stimulating committing these crimes on the, on the one hand, and pacifying the victims and preventing them to retaliate, on the other hand. The non-penal prevention which is beyond the scope of criminal system in situational prevention contains actions such as warning, special envoys, introducing peace keeper, boycott, humanitarian military intervention, facilitating the escape of victims. In the scope of social prevention, it contains actions such as promoting human rights respect, boosting good government, facing stimulating and extremist ideologies, modifying hard living situations, settling disputes and expanding dialogue atmosphere, improving some cultural structures, reconciliation whit the past events and healing those affected by these crimes, improving media moralities reacting against human rights violations, restricting weapon contrabands, changing diplomacy logics from gaining profits to humanitarian causes. The given strategies may pave the way for preventing these crimes.