In this study, a carbon nanotube based flexible strain sensor was experimentally studied to develop a large deformable sensor. The sensor was made of silicone rubber and a multi-wall carbon nanotube as an electrically conductive filler with less than 3 wt% content. Since the nanocomposite sensor has piezoresistivity, its electrical resistivity is changed according to deformation. The sensor was fabricated as a sandwich structure to prevent buckling under large deformation and the electrodes were made with conductive fabrics to be able to connect it on large deformable materials. Flexible strain sensors are less sensitive than commercial strain sensors, but can have sufficient sensing characteristics to be large strain sensors. The output voltage range of the sensor can be enough to cover the large deformation of the sensing object completely due to it lower sensitivity. Further research should develop a high hysteresis compensation algorithm due to viscoelasticity to obtain more accurate rubber parts deformation measure.