Abstract:The conventional histological method and scanning electron microscopy were used to observe the development of skin,external gills,and pharynx in larval,sub-adult and adult individuals of Onychodactylus fischeri. The results showed that skin was thickened with the increase of age. The dorsal skin and ventral skin were not different in thickness at larval stage,while the skin on the back was thicker at sub-adult and adult stages. The external gills was an important respiratory organ at larval and sub-adult stages,while it was gradually degraded after sub-adult stage. Pharynx and oral cavity were not developed well at larval stage,while pharynx was gradually developed at sub-adult stage,and developed well to become an important respiratory organ at adult stage.