Abstract Cement and emulsified asphalt mortar (CA mortar) consists of cement, emulsified asphalt, sand, water, and other additives, which can be used as a vibration attenuator and isolation casting layer in modern high-speed railway. However, the dynamic mechanical properties of CA mortar have not been well documented until now. In this paper, a series of experiments were carried out to characterize the dynamic properties of CA mortar. It can be found from the test results that the compressive strength, the compressive strain, and the elastic modulus are much more sensitive than traditional Portland cement mortar and concrete in a specified range of strain rate. Meanwhile, experimental results from an impacting acceleration test presents that CA mortar had excellent vibration attenuation and isolation functions.