Pentamode metamaterials (PMs) are one of the artificial periodic materials for which the six eigenvalues of the effective elasticity tensor only take one non-zero but five zero. Hence，PMs are also called “metafluids” by making the bulk modulus B extremely large compared to the shear modulus G. PMs with anisotropic elastic tensor have potential applications for acoustic cloaking, noise insulation, and other special acoustic devices. So it is concerned by scientists. In the review, pentamode materials and their recent progress are introduced. It includes the concept of PMs, acoustic and elastic properties of Bragg scattering PMs, locally resonant PMs, fabrications and measurement methods.