Light environment provides signals for plants to develop and accomplish their life cycle successfully. Those signals are perceived and transduced by photoreceptors. Phosphorylation is one of the biochemical mechanisms initiating light signalling cascade and is a challenging question in the photobiology field today. Here, we study early light-induced phosphoproteome in Arabidopsis thaliana through a Label free LC-MS/MS proteomic approach to identify proteins which significantly change their phosphorylation status in a light-responsive way. And investigate the participation of the photoreceptors during light-dependent phosphoroylation changes.