The paper deals with the basic notion of policy development with reference to Australian Mandatory Detention Policy. In explaining social policy making, first the concept of social policy has been discussed. Then the basic types of policy development, namely the top-down approach and the policy cycle have been discussed. It shows that the top-down approach is somewhat rigid in nature. Therefore, a more dynamic and open process has to be adopted. The policy cycle, an open-ended and interactive mechanism provides the required dynamism. And Australia has adhered to this method. Further, Mandatory Detention Policy has been reviewed as a social policy. And it has been observed that, though necessary for security purposes, kit violates basic human rights and international laws. In terms of justice and fairness, this policy does not qualify as of welfare.