Abstract: The gas flow shape of the aqueous vapor micro-plasma arcis closely related with the arc shape and arc characteristics.The gas flow shape and arc pressure of micro-plasma arc with different medium aqueousvapor are presented.The different mediums are water,aqueous alcoholand aqueous acetone.The results show that water medium arc gas flowexpansion rate is the largest,and the aqueous acetone medium arc gasflow expansion rate is the smallest.The gas flow expansion rate is extend~ed with increasing of the consistency of aqueous alcohol or aqueous ace-tone.The arc pressure of water medium arc is the smallest,the arc pres-sure of the aqueous acetone medium arc is the biggest.The arc pressureis increased with increasing of the consistency of aqueous alcohol or aqueous acetone.The cutting characteristics depende on the arc shape,gas flow and arc pressure.In same conditions,the cutting speed is the fastestin acetone medium aqueous vapor plasma arc,and the slowest in watermedium aqueous vapor plasma arc.