The invention relates to a packaging bag, which is provided with a tubular passage which leads to the outside of the packaging bag. The opening of the packaging bag is arranged at the end of the tubular passage. The tubular passage not only can be used as an inlet/outlet passage for filling articles into the packaging bag, but also can knotted in use under the situation that the packaging bag is required to be closed. The knotted tubular passage closes a passage which leads to the outside of the packaging bag. When the passage is needed to be opened again, the tubular passage is only required to be unknotted. By using the packaging bag provided by the invention, the situation that packaged commodities cannot be used up at one time can be very conveniently coped with and the packaging bag is suitable for packaging various commodities. The packaging bag provided by the invention can also be used as a beverage bag with a straw, a urine collection bag for men and a water-filled heavy object bag.