Disclosed is a method of adjusting a starting point of a peer, the method including receiving a starting point value and a downloading point value of a counterpart peer from the counterpart peer, determining an initial starting point value of a peer based on the received starting point value and the received downloading point value, calculating a ratio between an average play point move rate (APMR) of the peer and an average fragment reception rate of the peer when the determined initial starting point value is less than the received starting point value, calculating a margin based on the calculated ratio, and determining the starting point value of the peer using one of the received starting point value and the received downloading point value, and the calculated margin.