The present application relates to an electrode member, an electrode assembly and a secondary battery. The electrode member comprises an electrode body and a conductive structure that has a first portion having an active material and a second portion extending from the first portion. The second portion comprises a main portion and a transition portion provided between the main portion and the first portion, and a width of the transition portion larger than a width of the main portion. The conductive structure is welded with the second portion and extends along a direction away from the first portion. At least a part of a welding region formed by the second portion and the conductive structure is positioned at the transition portion, thereby avoiding the overcurrent area being significantly reduced by the main portion and ensuring that every position electric current passes through have a sufficient overcurrent area.