A system of controlling an antenna of a moving object is provided. The system includes: a plurality of communication antennas established in the moving object; an environmental information generation unit generating environmental information which includes strength information of a received signal and moving speed information of the moving object; an antenna use determination unit determining, with respect to the plurality of communication antennas, a number of antennas for each use based on the environmental information; and an antenna assigning unit assigning the plurality of communication antennas for each use according to the determined number of antennas.