Abstract: The micro-morphology of leaf abaxial epidermis of 12 species (including varieties and forma) of Fimbristylis from shandong were studied under light microscope.The results show that Fimbristylis is highly consistent in the micro-morphological characters, e.g. the shape of long-cells long-tubular or short-tubular, rarely sub-tetragonal or polygonal,the margin of cell wall sinuate, sinuolate to straight; short-cells between the vein absent; prickle hairs only exist in rare species; stomas between the vein mostly 2 columns, rarely 2~4 columns;subsidary cells dome-shaped to triangular,dome-shaped, rarely parallel-sided. The leaf abaxial epidermis can be divided into two types: the prickle hairs exist and absent. According to morphology and micro-morphology of leaf abaxial epidermis, F.complanata (Retz.) Link var. kraussiana C. B. Clarke should be rehabilitated to species rank F.kraussiana Hochst et Steud. and F.dichotoma (L.) Vahl F. depauperat（C. B. Clarke）Ohwi is treated as F.dichotoma (L.) Vahl var. depauperata（C. B. Clarke）F. Z. Li et L. N. Liu comb. & stat. nov.

Key words: Fimbristylis Vahl, leaf abaxial epidermis, micro-morphology, Shandong