In this thesis, we report the investigation of translational and rotational diffusion behaviors of merocyanine 540 in viscous fluids with anisotropy fluorescence correlation spectroscopy (FCS). Our experimental result supports that the molecule is an oblate ellipsoid. The extracted viscosity values match almost perfectly with the ones measured by viscometer. Our study demonstrates that anisotropy FCS is indeed a powerful method to examine microscopic hydrodynamic behaviors.