The thermoplastic deformation behavior of the Mg(58)Cu(28.5)Gd(11)Ag(2.5) metallic glass composites (BMGCs) reinforced with porous Mo particles was studied by means of thermal scanning calorimetry (DSC), thermal mechanical analysis (TMA) and high-temperature compression test in the supercooled liquid region. Based on the result obtained from DSC and TMA, the deformation behavior for Mg(58)Cu(28.5) Gd(11)Ag(2.5) BMGC rod was investigated by compression test at different strain rates (1 x 10(-2)-1 x 10(-1) s(-1)) and temperatures in the supercooled liquid region, namely 433 K, 438 K. and 443 K. The flow stresses obtained at a constant strain rate of 1 x 10(-2) s(-1) decrease with increasing temperature and reach a low stress about 10 MPa at 443 K. In addition, the X-ray diffraction results confirm that the Mg(58)Cu(28.5) Gd(11)Ag(2.5) BMGC samples remain the amorphous nature after compression at 443 K. The current results indicate that the Mg(58)Cu(28.5)Gd(11)Ag(2.5) BMGC possesses an excellent superplastic formability with the m-value (strain rate sensitivity) greater than 0.7 in the supercooled liquid region of 438-443 K at a strain rate around 1 x 10(-2) s(-1). (C) 2010 Published by Elsevier Ltd.