A compressed pulse signal obtained when a linear FM signal has gone through a matched filter has a typical waveform of a sampling function. This means that energy of a compressed pulse signal is concentrated near its center peak as is the case with the sampling function. Taking into account this characteristic, we estimated energy distribution of a compressed pulse signal from energy distribution of the sampling function. It has been confirmed that, compared with the conventional method which detects amplitude components, this new method of compressed pulse signal detection provides an improved detecting ability even when the compressed pulse signal is in a status expressed by a cross-correlation function due to underwater propagation loss or phase distortion caused by multipath propagation.