A data bus system, capable of distributing devices including first and second data buses capable of transmitting data among a plurality of devices; a register block that stores information on a first bus request signal and a first bus grant signal; a global arbiter that receives the first bus request signal from the register block to output a second bus request signal and receives a second bus grant signal from the register block to output the first bus grant signal. A bilateral bridge that acts as a data transmission path between the first data bus and the second data bus; and a local arbiter exists in each first and second data bus, and receives the second bus request signal from the global arbiter to output the second bus grant signal is disclosed.