Abstract: The broadband computerized measuring system was used in studing and analyzing the ultrasound backscattering spectrum of a series of mammalian animal soft tissues.It has been shown that the backscattering for various soft tissues of pig increases in the following order:spleen,kidney,heart and liver,and the backscattering of bovine liver is larger than that of pig.Bovine heart and pig heart exhibit anisotropic backscattering character.On the basis of the scatter theory of nonhomoge-neous continuous medium and the histological knowledge the authors have focused the discussions on the scattering mechanism of various tissues and obtained satisfactory explanation for backscattering behavior of all the tissues investigated.