In this papet,an improved theory about propagation of sound in highly concentrated suspensionsis elaborated.The effects of multiple scattering among suspended particles are taken into accountnot only for compressional wave but also for thermal wave and Viscosity wave.Supposing that thewavelength of scattered compressional wave is much larger than the diameter of suspended particles,we have found out the sound field near a particular particle produced by the thermal wave and viscouswave scattered from other particles by introducing proper statistical hypotheses.Hence,the rigoroussolutions can be obtained by means of the boundary conditions of the particle.The formulas forcalculating the effective density and effective bulk modulus of suspensions are derived in the paper.For two typical concentrated suspensions,namely,coal slurry and soil slurry,numerical results arecalculated and discussed. In this papet, an improved theory about propagation of sound in highly concentrated suspensionsis elaborated.The effects of multiple scattering among suspended particles are taken into account only for compressional wave but also for thermal wave and viscosity signal. Suding that the wave length of scattered compressional wave is much larger than the diameter of suspended particles, we have found out the sound field near a particular particle produced by the thermal wave and viscouswave scattered from other particles by introducing proper statistical hypotheses .ence, the rigoroussolutions can be obtained by means of the boundary conditions of the particles. The formulas forcalculating the effective density and effective bulk modulus of suspensions are derived in the paper. For two typical concentrated suspensions, namely, coal slurry and soil slurry, numerical results arecalculated and discussed.