Abstract: A filter tip used by a cigarette has at least one screw-like tunnel. Adopting the above structure, under the premise of not increasing air clogging, the screw-like tunnel of the present cigarette filter increases path length of the smoke crossing the cigarette filter and enlarges adsorbing area of the cigarette filter to injurant in the smoke, so as to achieve the object of improving filtering effect of the cigarette filter of a cigarette.