The present invention aims to provide an RF coil assembly capable of eliminating the need for connecting and disconnecting an electric path at decoupling portions and is an RF coil assembly including: a plurality of coil loops that are adjacent to each other in sequence and construct a phased array; and a plurality of decoupling device that cancel electromagnetic coupling between adjacent coil loops, respectively, wherein at least two of the plurality of coil loops are two coil loops that are adjacent to each other across a boundary where they can be decoupled from each other, and wherein at least one of the plurality of decoupling device is two coils that are connected in series to the two coil loops, respectively, and are opposed to each other across the boundary and form a pair of coils for decoupling.