A gardening shears includes two handles, a first shear blade connected to one handle and providing a suspension arm portion, a linking rod connected to the other handle, a second shear blade coaxially pivoted to the first shear blade and the linking rod and providing an elongated slot, and a control unit including an arched guide member fixedly connected with its one end to the linking rod and a guide wheel pivotally connected to the suspension arm portion of the first shear blade with a guiding protrusion thereof inserted into the elongated slot of the second shear blade. Thus, when opening and closing the handles, the mating arrangement of the arched guide member, the guide wheel and the elongated slot of the second shear blade enables the first and second shear blade to implement the shearing action twice.