Xbee S1, accidentally plug the IO0 (pin 20) and the IO4 (pin11) to VCC (3.3V) and GND.I broken my Xbee?

No you have not as both pins are designed to accept 0 and 3V VCC.

Right, Thanks for reply! I got suspicious because my Xbee seemed to be dead but I discovered that it was only a bad contact between the Xbee and the pin header, due to a manufactory problem on the pin header. I confirm that 3.3V on pin 20 don’t damage the Xbee.