A mobile IPTV system and a method of providing a mobile IPTV service are provided. The mobile IPTV system includes an IPTV head end, a base station, and a mobile terminal. The IPTV head end encodes data for an IPTV stream into a base layer and an enhancement layer and outputs the encoded data. The base station receives the IPTV stream from the IPV head end and partially truncates the enhancement layer of the IPTV stream according to a combination of a modulation technique and a cording rate which are determined in advance and outputs a transmission IPTV stream. The mobile terminal receives the transmission IPTV stream from the base station. Since an IPTV service is provided in view of a user distribution characteristic of a network, user can be efficiently provided with satisfactory QoS.