The next generation of high energy physics experiments and time-of-flight positron emission tomography imaging require scintillators with ultrafast decay ranging from nanoseconds （ns） to picoseconds （ps） to fulfill the need for higher precision of radiation detection. The Cs₂ZnCl₄ crystal stands out due to its remarkable advantages of an ultrafast decay without slow component， a low melting point， non-hygroscopic， as well as the proper emission band matching well with commercial photomultiplier tube. In recent years， Cs₂ZnCl₄ crystal has attracted worldwide research interests as a kind of ultrafast scintillator with core-valence luminescence （CVL）. This review emphasis on the research history and progress of Cs₂ZnCl₄ crystals， including luminescence mechanism， physicochemical properties， crystal growth techniques and the scintillation properties. Particularly， emphasis is placed on the optical and scintillation properties of Cs₂ZnCl₄ crystal. The application potential of Cs₂ZnCl₄ crystals as a unique ultrafast scintillator is then concluded.

Cs₂ZnCl₄;ultrafast scintillator;core-valence luminescence;crystal growth;scintillation performance