Abstract: The safely operation with multiple electrodes is important for arc heater running re-liability with large arc current.The influence of ballast resistor settings,gas flow and arc current were observed for arc heaters with a pair of cathodes matching single anode,and with a dual elec-trodes separately.Results show that the ballast resistor settings is the key factor for division of current between electrodes,and the operation parameters such as gas flow and current are insen-sitive with the arc current distribution.For arc heater with a pair of cathodes and single anode, ballast resistors with the certain difference connected simultaneously to inner and outer cathodes is a necessary for division of current between cathodes.For arc heater with a dual electrodes,the division of current between each electrode could be successfully achieved so far as the ballast re-sistors connected to cathodes.And the different current distribution proportions could be a-chieved by adjustment of the ballast resistor.When arc heater operated in multiple electrodes mode,the ballast resistor settings with lowest power loss and uniform division of current should be selected.