Abstract: the paper discussed some problenis in inter pretation sedimentary environment interpretation using size analysis。It is considered that no direct relation-ship enists between the size distribution andsedimentary environments,and only indicatesthe former the hyrirodynamic conditions duringsedimentation.By the study of the vertical varation low of size curves and indices(i.e.sizeCurve and indice sequence analysis),it is possi-ble to determine relativety accurately sedimen-tary environments.