All experimental data available on a low‐temperature optical dephasing for H,‐octaethylporphin guest molecules in an amorphous polystyrene host are discussed in relation to spectral diffusion processes. Some data published earlier have once more been thoroughly studied and some corrections introduced, also some new data are presented. A notable dependence of the holewidth on a burning wavelength within the inhomogeneously broadened 0–0 absorption band at T = 0.05 K has been observed. The spectral diffusion is found to be actual at T = 1.45 – 7 K and is not at T< 0.05 K and at T>8 K.