In this work I represented Janus as a god of all passages and doors. Most of his characteristics are known from Ovide's first book of Fasti. What is the most specific about Janus, is his ambiguality. He is a symbol of everything that is double. The number of his epithets is numerous and we can relate Janus to other gods of Roman Pantheon. He is old and always at the beginning, which is reason why he was invoked in prayers always first. The best proof oh his inception is in Carmen Saliare where they put him as the god of gods. There are also some similarities between Janus and Etruscan gods Ani and Culsans. Janus is compared even with the Greek god Boreas, though Greeks never had a divinity that could be called Janus. His symbols are a key and a stick in his hands and two-faced head. Not rarely he is identified with the sun, the moon, changes, time,beginnings, passages etc.