The preparation of multi-walled carbon nanotube/polylactide (PLA)/Ecoflex® biodegradable composites is described. Three modifiers, maleic anhydride ,methyl methacrylate and vinyltrimethoxysilane , were utilized to modify multiwall carbon nanotube. The dispersion of multi-walled carbon nanotube was enhanced by covalent or hydrogen bonding between modified multi-walled carbon and biodegradable blend. The tensile strengths of pristine PLA/Ecoflex® resin and 4 wt% modified multi-walled carbon composites are 68 kgf/cm2 and 257 kgf/cm2, respectively (representing a difference of 380%). High electrical conductivity can be achieved at a low carbon nanotube loading. When 1wt% modified multi-walled carbon was added to PLA/Ecoflex® matrix, the surface resistance of the composite fell from 1.46×1016 to 7.88 × 102 Ω/Υ (by 1013 order).