A simple 2£3 reconflgurable beam-forming network (R-BFN) for four-beam reconflguration application is designed and implemented. The proposed R-BFN with two input ports and three output ports consists of a 2:1 power divider, a 90 - hybrid, a 180 - hybrid and a 2-bit phase shifter. The 2- bit phase shifter has two states: one is a 180 - phase shifter (State 1); the other is a 0 - =360 - phase shifter (State 2). By introducing the 2-bit phase shifter, the constant phase difierences of three output ports can be reconflgured. When the proposed R-BFN is connected to an antenna array, a four-beam reconflguration is obtained. Simulated and measured results show that good impedance matching, high port isolation, equal power division, and constant phase difierence have been achieved simultaneously within the operation band of 2.4{2.6GHz. The capability of the proposed R-BFN to reconflgure beams is also verifled experimentally by using a 2.5GHz dipole array.