In longitudinal sections, T. vaginalis visualized by TEM was round or ovoid with an ovoid nucleus situated close to the anterior one-third of the body. There was an independent and well-developed Golgi complex dorsal to the nucleus and parabasal filaments. The anterior end of the cell had a blepharoplast complex which consisted of three parts, i.e., periflagellar canal, C-shaped structure of the pelta in the wall of periflagellar canal and five blepharoplasts. Four anterior flagella and one posterior flagellum were extended respectively from each of the blepharoplasts, simultaneously with one costa and two parabasal filaments. The axostyle was divided into three parts, i.e., capitulum, trunk and caudal. The spoon-shaped axostylar capitulum originated from the peltar-axostylar junction was composed of many microtubules and extended around the side of the nucleus posteriorly and turned itself at the end of the nucleus forming an axostylar trunk which projected externally in the form of a spicule.