  Our aim of this and subsequent papers is to enlighten (a part of, presumably)
arithmetic structures of knots. This paper introduces a notion of profinite
knots which extends topological knots and shows its various basic properties.
Particularly an action of the absolute Galois group of the rational number
field on profinite knots is rigorously established, which is attained by our
extending the action of Drinfeld's Grothendieck-Teichm\"{u}ller group on
profinite braid groups into on profinite knots.
