In this paper, we present a new reconfigurable element using p-i-n diode for reconfigurable reflectarray antennas. The element cell is realized using a single substrate, a ground plane and only a single p-i-n diode embedded in the element, hence very low complexity. Two phase states with a step of 180° at 11.5 GHz is achieved through controlling a p-i-n diode. The element structure is optimized by a full wave simulation. A prototype of the element is fabricated and measured to verify the design. Experimental results show an excellent phase control capability according the state of switch.