Abstract:Objective:To probe into the morphology and distuibution characteristics of calcium oxalate crystals in several kinds of Cinnamon bark.Method:Forty samples of ten different species of Cinamomi Cortex were examined,and the inter cellular calcium oxalate crystals in the phloem rays were observed by optical microscope and scanning electron microscope.Result:It was found that for samples of the same botanical origin,there is little variation in the crystal morphology following certain regularity.The amount,size and ultra-micromorphologic characteristics are influenced by various factors.Conclusion:The pattern of morphology and distribution of calcium oxalate crystals may well be an index for identification of the crude drug of Cinnamon bark.