Terrace is characterized by unique planar and vertical morphology.However,its planar morphologicalcharacteristics can not be depicted accurately by the existing terrace classification,which makes the existing classification difficult to meet the needs of constructing a terrace digital analog model in the future.By taking drought terraceas a key point,the general characteristics,planar and vertical morphological characteristics,and measurablegeometric characteristics of terraces are studied in detail.A new classification of terraces based on the planarmorphological characteristics is put forth.Based on the combination with existing classification,a comprehensive digital classification of terraces is presented.Compared with the traditional classification of terraces,the new comprehensive classification fully considers the general characteristics,planar and vertical morphological characteristics and measurable geometric characteristics of terraces and can better depict the specialmorphological and measurable geometric characteristics of terraces.The results lay a solid foundation for theconstruction of a terrace digital analog model in the future and have important theoretical significance for theeffective digital representation and analysis of terraces by using digital elevation model.