A multifunctional recumbent exercising device is disclosed, including a base frame, a first transmission unit, a first retracting unit, a resistance unit, a first guiding piece and a first movable seat. By changing a relative position between the first movable seat and the first guiding piece, the position of a first slide-assistance portion of the first movable seat on the base frame can be changed. The multifunctional recumbent exercising device allows an operator to apply force to a first side or a second side of the base frame, in order to select various kinds of training modes.