Chlorophyll fluorescence is an effective tool for investigating characteristics of any photosynthesizing organisms and its responses due to different stressors. Here, we have studied a short-term temperature response on three Antarctic green algal lichen species: Umbilicaria antarctica, Xanthoria elegans, and Rhizoplaca melanophtalma. We measured slow chlorophyll fluorescence transients in these Antarctic lichen species during slowely cooling of thallus temperature from 20°C to 5, 0 and-5°C with 20 minute acclimation at each temperature. The measurements were supplemented with saturation pulses for the analysis of chlorophyll fluorescence parameters: maximum yield of PS II photochemistry (F V /F M), effective quantum yield of PS II photochemistry ( PSII) and quenching parameters. In response to decreasing thallus temperature, we observed species-specific changes in chlorophyll fluorescence parameters as well as in the shape of the chlorophyll fluorescence transients. We propose that species-specific changes in the slow phase of chlorophyll fluorescence transients can be potentially used as indicators of freezing stress in photosynthetic apparatus of lichen algal photobionts.