Abstract: AIM:To observe the morphology of Blastocystis hominis .METHODS:The morphology of Blastocystis hominis found in the fecal specimens from school children and diarrheal cases was examined by using normal saline smear,iodine stain and iron hematoxylin staining method in Ali,Xizang Autonomous Region and Xinjiang Autonomous Region.RESULTS:The morphology of Blastocystis hominis was found to include four types,namely vacuolized,granular,amoeboid and binary fission. CONCLUSION: The vacuole type was the most often seen and accounted for 84% of all 4 types. Blastocystis hominis infection was often found to be associated with Entamoeba coli and other in testinal protozoa, leading to diarrhea in these patients.

Key words: Blastocystis hominis, intestinal protozoa, morphology