Photoacoustic spectrometer (PAS) is a significant technique to measure the thermal diffusivity of any material. When modulated light interact with solid sample which is covered by aluminium or other metal plate, first the light is absorbed by the sample and then thermal energy emitted due to non-radiative decay. Thereafter, acoustic wave produced due to different temperature which maintain by an optical chopper. The medium inside the cavity expands or retract according to the chopper frequency. So, the generated pressure fluctuation inside it measures by using a sensitive condenser microphone which fitted inside the cavity by a narrow path. Here the authors successfully synthesized molybdenum disulfide (MoS2) and its nanocomposite with graphene oxide (MoS2-GO) by simple hydrothermal method. The XRD and FESEM data confirm the phase and morphological structures of the synthesized material. The thermal diffusivity of MoS2 and MoS2-GO nanocomposite are obtained 10.94 mm2/s and 14.72 mm2/s respectively.