We studied the depinning of the magnetic field-induced spin-density-wave of the organic superconductor (TMTSF)2ClO4, stabilized above 4T and at 300mK. For the sample cross-sectional area of 9.9 × 10-4cm2, the quantized Hall resistance begins to decrease when the sample current increases more than 160μA. One the other hand, the longitudinal resistance at least fifteen times as small as that of the transverse resistance in the quantized Hall region, increase when the non-Ohmic behavior appears. The depinning is observed only in the negative Hall plateau region between 6.2 and 6.8T. No departure from the quantized Hall behavior is observed neither above 7.1T nor below 6.2T.