We intended to get one method to measure actual pressure occured on fore poppet of ship during its launching. It is almost impossible to confirm actual pressure and its variation on fore poppet based on travel, and there has been no simple and reliable method to confirm them so far. Here we have devised one method there-of. Four steel load cells are used as one unit having strain gages pasted around its side and put aline in a flat steel box. This unit is installed between wooden fore poppet and sliding way at six points. We could measure actual pressure and its variation of the above six points at both of port and starboard side 1y this device.