A new pulsed jet device is presented which can produce oscillatory pulsed wafergas jet. This device is used in the erasive experiment on the while sandbrick whose compressive resistance is 30 Mpa. The curves of the erasive effects of the oscillatory pulsed water-gas jet.the oscillatory pulsed jet and the ordinary jet are drawn in order to be compared.which are changed as the distances of the targets are changed. In addition the reason why the erasive effect of the new jet is superior to the other two jets is analyzed.