Delay tolerant network (DTN) challenges on large delay of communication, opportunistic and intermittent connectivity so that data can be transferred over vulnerable network. Most routing protocols in DTN basing on replicating routing work well over infinite buffer assumption but the performance drops when using with finite buffer due to the congestion problem. However, it is still lack of work on congestion control in DTN. Since simple congestion control policies can cause uselessly looping problem and cannot maintain high performance when nodes buffer become overflow, a new buffer management policy for DTN should be considered. In this paper, we identify the looping problem caused by using simple buffer management policies and propose the Effective Looping Control mechanism to solve such a problem. We also propose the Creditbased Congestion Control as for heuristically deleting messages when the buffer congested to retain high delivery rate with low number of replicas. Key w...