A compact micro-strip printed antenna with reconfigurable frequency for the intelligent robot is proposed. The antenna is fabricated on FR4epoxy substrate and consists of a main rectangular ring, an additional rectangular resonant band, two elliptical rings and a defected ground structure (DGS). By purposefully controlling two PIN diode switches, three reconfigurable frequencies for Bluetooth, WiMAX (worldwide inter-operability for microwave access), WLAN (wireless local area network) and RFID (radio frequency identification devices) systems are realised. As a traditional monopole, the antenna is omnidirectional and has high gain. Meanwhile, the simulation results are in good agreement with the measured results.