Ploidy level of 55 Dendrobium was identified by using squash method,and the length and density of stoma,the length,width and thickness of leaf,the height of plant,the diameters of the stem and the flower and the thickness of petal were also measured.The results showed that:(1)55 Dendrobium resource were composed of 40 tetraploids,11 triploids and 4 diploids,with tetraploid resources,triploid resources and diploid resources accounting for 72.73%,20.00% and 7.27%,respectively.(2)According to the correlation analysis of the chromosome ploidy and 9 morphological traits in Dendrobium,the chromosome ploidy is significantly negatively associated to the dense of stoma and is significantly associated to the length of stoma,the width and thickness of leaf,the diameters of the stem,the diameter of the flower and the thickness of petal.There was not significant coorelation between the chromosome ploidy and the height of plant in the Dendrobium.