OBJECTIVE： To compare and study morphology and histology of 5 Rumex species， and to provide evidence for specie identification of Rumex and the formulation of quality standard for Rumex madaio. METHODS： The original plant identification， morphological identification and microscopic identification methods were adopted to compare Rumex patientia， Rumex crispus， Rumex hadroocarpus， Rumex dentatus and Rumex maritimus in respects of basal leaf morphology， inner tepal， cross section of root and medical material power. RESULTS & CONCLUSIONS： There were differences among 5 Rumex species in respects of original plant morphology， root property， transverse section and powder microscopic characteristics. The edge and morphology of basal leaf and inner tepal in flower and fruit period were different greatly. Abnormal vascular bundle of transverse section could be used as identification points of Rumex species.