A new sample cell has been developed for measuring thermal diffusivity of a liquid sample at room temperature. The validity and usefulness of the sample cell presently developed was confirmed by determining thermal diffusivity values of water and five organic liquids. The results were found to agree well with the literature values. The sample cell was also applied to evaluate thermal properties of suspension with Ni-Zn nanoparticles. The thermal diffusivity values of Ni-Zn nanoparticle suspensions linearly increase with increasing the particle concentration and the increment of the 0.1mol/l sample case is found to be about 9% as compared to the solvent alone.