To provide a bag partition with movable pockets which solves the problem that though bags with pockets are frequently seen, they are not easily used for everyone and even when the bag is changed to another bag, it is troublesome to move all contents to the new one, and further, when the kind of the bag is changed for another one, the contents are dispersed in the other bag.

A cover body with an attaching/detaching mechanism is set on the core material of a base member. A space can be more effectively used by attaching respective sizes of pockets with attaching/detaching mechanisms in an arbitrary position/angle. Once the pockets are attached to the base member, contents are quickly moved to the new one by moving the pockets as they are even when the bag is changed to the other one.