通过分析沉积物声波测量过程能量损失的实质，阐述平行轴差距衰减测量法和垂直轴差距衰减测量法的研究基础——差动式衰减测量方法原理，并推导了其衰减系数公式。根据南海沉积物的柱状样品分装的特点，结合以上两种方法，提出了同轴差距衰减测量法，这种方法具有原理上的合理性并且其可操作性强；运用此方法测量了沉积物在常温和温度控制变化条件下的声波信号，计算了衰减系数，研究了温度对沉积物声波传播能量的影响，得出南海深水海底沉积物具有以下声衰减特性：沉积物含砂量高，声衰减系数大；随着温度的升高，沉积物的声衰减系数变化具有不均匀性，整体呈非线性减小趋势。以上研究将为声学遥测和反演海底沉积物的物理力学特性提供数据和方法支持。

The authors analyze the essential energy loss during sediment acoustic measurement process, describe the principle of differential attenuation measurement that is the research base of parallel-axis and vertical-axis differential distance attenuation measurement methods, and deduce its attenuation coefficient formula. According to sectioning characteristics of the cylinder seafloor sediment samples from the South China Sea, a coaxial differential distance attenuation measurement method (CDDAMM) is put forward with combination of the above two methods, which is reasonable in principle and feasible in practice. Using CDDAMM, they measure the sound propagation signals of the sediments in both room and controlled temperatures, calculate the acoustic attenuation coefficient, and study the effect of temperature on sound propagation energy. The sound attenuation characters of deep-water seafloor sediments from the South China Sea are as follows. The sediments have large acoustic attenuation coefficients with high sand contents. As temperature increases, the attenuation coefficients vary nonlinearly and inhomogenously, with a descending trend on the whole. This research has provided both data and method for acoustic remote measurement and inversion of physical and mechanical properties of seafloor sediments.