Recent experimental and theoretical advances in the field of depolarized light scattering from monatomic fluids and from tetrahedral molecular systems are reviewed. Molecular mechanisms for collision-induced polarizability, which are the microscopic basic for depolarized light scattering, are examined. The line shapes obtained from experimental or molecular dynamics results of various authors are compared. In the case of dence fluids, in the low frequency part appears as Lorentian, while the overall line shape is exponential. Molecular motions of the thermal fluctuations suggested from experimental and molecular dynamics results are discussed. The Dipole-Quadrupole polarizability mechanism for the tetrahedral molecular system is examined and compared with the existing experimental results.