The systematics study of cestode parasites of cartilaginous fishes from Iranian waters has been started recently and since that more than ten species have been described. Cestoda are the most diverse and abundant parasites in the spiral intestine of elasmobranchs. Tetraphyllidea is the greatest order in these fish with 12 genus and more than 200 species. The genus Alexandercestos Runke & Workman, 2013 was introduced first in 2013 and so far two species from Negaprion Whitley, 1940 have been described. Sampling was carried out in the Jood village off Gulf of Oman on May, 2015. The worms stained with Delafield's Hematoxylin and Scanning Electron Microscope (SEM) images were prepared. The new species in the current research is the third species in the genus. The total length of new species is 6-8 cm and the number of proglottids is 100-130. This new species possess four uniloculate bothridia with an apical sucker, in addition to neck scutes. More information about the other characters will be presented.