Abstract: A new method and an apparatus concern improvements of blowing mortar or concrete on the feeding compression air, in which dry-mixed materials are quantitatively jetted from a nozzle at a blowing machine, and liquid is supplied by determined amount bearing on the compression air current through the nozzle, so that grains of the materials are mixed with the liquid while feeding the materials, and the property of such material is changed from dry condition to wet condition of determined water-cement ratio, and the thus changed material is jetted from a nozzle at the end of a hose.