Absorption, fluorescence and delayed luminescence (in ps time range) of cyanobacterium Tolypothrix tenuis (Kutz) adapted to green (GR) and red (RR) radiation and dissolved in 15% polyvinyl alcohol Solutions were measured. Fluorescence and delayed luminescence depended on the adaptation to radiation and the wavelength of fluorescence excitation. This suggests that paths of deactivation of excitation in pigment-protein complexes present in organisms adapted to GR and RR differ.