Fish trypanosome is a kind of flagellated parasitic protozoa which parasitizes in the blood of fish，causing harm of fish and economic losses.Clinical signs of the disease include depressed,general oedema and visceral hemorrhage.But the taxonomic of trypanosome and basic research is quite limited and backward.During the parasite fauna investigation,a freshwater fish trypanosome was isolated from the blood of crucian carps.According to the morphological comparison between the trypanosome we got and other trypanosomes data,it was identified as Trypanosoma pingi and was redescribed using 13 morphometric characterizations.SSU rDNA sequences were also compared.The sequence alignments revealed that the present SSU rDNA sequence was most similar to that of Trypanosoma pseudobagri (94.62%),but the morphological variation were significant different,suggesting that T. pingi and T. pseudobagri might be different genotypes.