The conductive polymer nanocomposite (CPC) of multiwall carbon nanotubes (MWNT) filled Polycaprolactone (PCL) was formulated by melt mixing method. PCL based conductive phase served as disperse phase, blended with polypropylene (PP) and polyamide 12 (PA12) respectively. The thermo- and chemo-electrical properties of mono- and bi-component CPC have been investigated independently. Results show that PP/PCL-CNT CPC is a good temperature sensor whereas no significant response was observed while exposing to toluene vapor. In contrast, PA12/PCL-CNT exhibits good vapor sensing capability instead of temperature sensor. It is assumed that PP phase prevents the diffusion of vapor molecules within PCL conductive phase. The vapor sensing results indicated that PP external matrix provides the CPC with higher barrier effects than PA12.