The fracture mechanics of glass bottles by using underwater shockwaves technique and the recycling process by smashing the glass bottles were discussed. The proposed smashing process can decrease the recycling cost by small grain sizing of "cullet" which is the crashed glass fragments and by overleaping the washing process as the recycling pre-processing. In this study, using commercial beer bottle, the relation between the "cullet" size and various explosive conditions, that is, distance, amount, speed and configuration were clarified.