Poly(propylene carbonate)(PPC),polymerized from propylene oxide and carbon dioxide has attracted considerable attention for its sustainability and biodegradability. Compounding PPC with nano-fillers is an effective way to improve its properties, overcome shortcomings and enlarge its application fields. In this work, a conventional processing method, melt mixing and hot pressing, was used to prepare PPC/multiwall carbon nanotube (MWCNT)composites with different MWCNT loading(0.3,0.5,1,3 and 5wt%). It was found that PPC/MWCNT composite has a percolation threshold as low as 0.3wt%, indicating that MWCNT could dispersed very well in PPC to form a conductive network. The resistivity of PPC/MWCNT composite with 0.5wt% MWCNT is 2400Ω•Cm and is only 14Ω•Cm for the composite with 3% MWCNT. SEM images show a homogeneous distribution of MWCNT clusters. An obvious plateau of storage modulus at low frequency was observed in the rheological results when MWCNT loading is above 0.5wt%.The piezoresistive behavior is investigated for specimens loaded in axial tension. The composites exhibit excellent conductive stability even though under a large strain, and the gauge factor of the specimens (MWCNT wt% from 0.5 to 2) is only 2 under 50% strain. Furthermore, the composites were subjected to 20 times cyclic strain (50% strain applied) and the resistance changed steadily and linearly with the strain except for the samples containing 0.5wt% MWCNT near the percolation threshold. These results demonstrated that the conductive polymer composites based on PPC and MWCNT can be a good candidate for strain sensors for large strain application. Keywords: Poly(propylene carbonate), MWCNT, Piezoresistive Behavior，strain sensor