A reconfigurable multi-mode multi-band transceiver for low power short-range wireless communication applications is presented. The low intermediate frequency (IF) receiver with 3 MHz IF carrier frequency and the direct-conversion transmitter support reconfigurable signal bandwidths from 250 kHz to 2 MHz and support a highest data rate of 3 Mbps for MSK modulation. An integrated multi-band PLL frequency synthesizer is utilized to provide the quadrature LO signals from about 300 MHz to 1 GHz for the transceiver multi-band application. The transceiver has been implemented in 0.18 um CMOS process. The measurement results show that the receiver achieves the noise figure (NF) and input 3rd order intermodulation point (IIP3) at the maximum gain mode are 4.9/5.5 dB and -19.6/-18.2 dBm in 400/900 MHz band, respectively. The transmitter working in 400/900 MHz band can deliver 10.2/7.3 dBm power to a 50 Ohm load. The transceiver consumes 32.9/35.6 mW in receive mode and 47.4/50.1 mW in transmit mode in 400/900 MHz band respectively.