Low-dimensional materials which possess extraordinary physical properties bring huge opportunities in advanced thermal management. Upon their large-scale applications, understanding the thermal transport properties is essential. However, the micro-to-nanoscale diameter/thickness leads to extreme difficulties in thermal characterization. Few techniques have been developed in past years targeting specific structures. Regardless of how it works, accurate temperature probing and evaluation of heat spreading is most critical. Laser-based spectroscopy technique, such as micro-Raman, characterizes thermal properties based on temperature response of Raman scattering. The temperature probing from distinct peaks determines that spatial resolution is not limited by the size of focused laser spot. Thus, it is capable of characterizing materials with dimension from macro down to nanoscale. This paper introduces the spectroscopy-based techniques developed in our lab for micro/nanoscale thermal characterizations. Raman as the primary one is detailed most. In addition, the advances of fluorescence spectroscopy techniques is briefly introduced. Due to the noncontact and non-destructive nature, the spectroscopy based technique has great potentials not only in micro/nanoscale characterization of thermos-physical properties, but also in extreme scale laser-assisted manufacturing field.