At low temperature, the vibration mode of K2OsO2(OH)4 in low wavenumber has no obvious change, but the O–H vibration in high wavenumber is affected by low temperature with some interesting phenomena appearing. Low temperature leads to the intensity of A_1g^((2)) increased as well as makes asymmetric stretching modes more distinguished. A perturbation of the crystal field caused by a contraction of the cell makes ν1 split into two components ν_1^' and ν_1^'' at –90 °C. Also, a reorientation of the coupled and hydrogen-bonded system in the lattice of K2OsO2(OH)4 occurs at low temperature makes a discontinuity of ν2 at this temperature.