The great extension of forests in the Djebel El Ghorra massif of El Kala National Park (north-eastern Algeria) allowed us to recognise three distinct forest formations: cork oak stands (Quercus suber), zeen oak stands (Quercus canariensis) and mixed oak (Quercus suber and Quercus canariensis) forest. Their peculiarities showed ideal ecological characteristics for the colonisation of corticolous lichens the two phorophytes. The three forest formations were sampled between 2017 and 2022. The identification of the taxa is based on stereo-microscopic examinations and usual chemical tests. Systematic surveys were conductedand allowed us to establish a list of 141 lichen taxa divided into 30 families.