A pouring port of a container for liquid at one end of which a rubber stopper allowing the penetration of an injection needle therethrough is embedded, wherein: the pouring port is formed by welding a port part, at least the innermost layer of which forming the discharge channel thereof comprises a resin containing a COP-based resin as the main component, with a stopper body part, which holds the rubber stopper and comprises a resin containing a COP-based resin as the main component, via the resin layers containing the respective COP-based resins as the main component and at least the resin constituting the stopper body part contains a rubber component in an amount of not more than 30% by mass, or has, in the main chain, a molecular structure represented by general formula (1) [wherein R represents a hydrogen atom or an organic group having 1 to 20 carbon atoms and n represents an integer equal to or greater than 1] and contains a PE-based resin in an amount of 30% by mass or less, and/or contains an antioxidant in an amount of 0.1% by mass or more and not more than 1.0% by mass.
