Controlled by an 1×3 optical switch, light from a pulsed broadband source was launched into one of 3 independent strings of 5 FBG sensors. By introducing suitable length of fiber as time delay between adjacent two gratings in the same string, the return signals can be selected by a programmable electric switch. Demodulation was achieved by using an unbalance Michelson scanning interferometer. Combined spatial and time division multiplexing operation was demonstrated successfully.