In this research, we propose a nanoscale and embeddable subzero temperature sensor that is made with a temperature-dependent titanium-oxide based metal-insulator-transition (MIT) device. For a nanoscale two-terminal structured MIT device, the MIT device's characteristics are noticeably changed from abrupt to gradual MIT under zero temperature, which is called MIT deformation. On the basis of the MIT deformation characteristics, subzero temperatures can be detected by reading current levels as temperature changes. Furthermore, this sensor has desirable sensing properties such as high-linearity and proper sensitivity. The obtained results strongly show that titanium-oxides with CMOS process compatibility, cost-effectiveness, nontoxicity, etc, can be applied at the nanoscale and embeddable on subzero temperature sensors on a chip.