Abstract: Diterpene synthases from plants are key enzymes in diterpene biosynthesis, which catalyzed the initial cyclization cascade of (E,E,E,)-geranylgeranyl pyrophosphate, and generated diverse carbon skeletons. Recent research show that the structural and stereo chemical differences lead to diverse natural diterpene compounds of plants. The structures of diterpene synthases play a crucial role in cyclization function. This article mainly reviews the mechanisms, functional characteristics, and structural information of diterpene synthases according to the crystal structures and functions.