An all-optaical fibre state-of-polarization controller (AOFSOPC) is first presented in this paper, which effectively changes the random state-of-polarization (SOP) of the single-mode fibre into a stable linear SOP. The SOP control is achieved without any mechanical, electrical or magnetical device. The characteristic parameters of the AOFSOPC fabricated experimentally have been measured with the insert loss and polarization sensitivity less than 1 dB and 0.5 dB, respectively.