This paper proposes reconfigurable hardware structures for spreading and scrambling of multi-mode CDMA systems. The proposed reconfigurable structures supporting IS-95, cdma2000 and WCDMA, include a pseudo noise code generator, a channelization code generator and a control circuit for signal flow control. The proposed reconfigurable structures provide an efficient hardware usage for multi-mode CDMA systems. The synthesis results show the area reduction about 24.7% compared with the original code generators. The proposed structures can provide efficient reconfigurability and high speed operations for future SDR systems.