The study was about the pioneer plant species which arise from the glacial retreat of the Pastoruri snow-capped as a result of the thaw that fluctuates between 10 and 12 meters per year. The studied area was the periglacial zone of the snow-capped, the retreat of this glacier is adduced to the climatic variability in the last years. Two families of plants - the Asteraceae and the Poaceae-were found in the area. In the first family, the existing species are: Senecio sublutescens Cuatrec., Baccharis tricuneata (L.f) Pers., Novenia acaulis Cuatrec., Xenophyllum dactylophyllum, V.A. Funk digitatum Funk., Senecio adenophyllus, and in the second family the species identified was the Calamagrostis ef. In order to evaluate the retreat of the Pastoruri glacier, the ice-covered area in the year 2001 was taken as the base point, and it was evaluated up to April 15, 2017, in which it was noticed that the retreat reached 20.95 %, this calculation was made using historical data from the National Service of Meteorology and Hydrology of Peru (SENAMHI), and the use of MAXENT software and Geographic Information System (GIS). It is concluded that the glaciers in the Cordillera Blanca are important indicators of the climate change; and that after these changes it is begun an altitudinal migration of the autochthonous plant species of the Andes taking up the spaces left by the retreat, and that sometimes these species do not adapt to the changes and disappear. This process affects the biodiversity of the flora.