To provide a container connection piece assembly, a spout member for a pouch container, and a body cap for a bottle container which are capable of easily and surely pouring the content liquid into a bottle container mouth part irrespective of the posture of the pouch container and easy in handling in refilling the content liquid from a flexible pouch container.

A container connection piece assembly 1 comprises a spout member to be joined with a pouch container 4 in a liquid-tight manner and a body cap 3 which is fitted to a mouth part 15 of a bottle container and guides the content liquid to be poured, the spout member 2 and the body cap 3 can be connected in the condition in which a spike needle part 24 is located inside a spout cylinder 6 and a liquid guide cylinder 25 is located outside the spout cylinder 6.