This project was carried out in the municipality of Yumbo - Valle del Cauca in order to propose an alternative that evidences the degree of affectation in which different areas are found due to air pollution where the use of lichens as quality bioindicators was analyzed. from air. A comparison was made between two areas, the first one includes the urban and industrial center of the Municipality of Yumbo, receiving influence from the high vehicular flow, the second is known as the Mulalo district and was determined as the conservation zone The first study area was subdivided into three zones, which were named by several names according to the monitoring stations distributed by the Municipality, these are the ACOPI, ECA Yumbo and Las Americas stations. In this area, a total of 21 forofitos were sampled, with 7 forofitos per zone and for area 2 15 forofitos were sampled, for each of which the liquid coverage count was performed by means of a staff of 20 cm wide by 30 cm long and a grid of 1 cm; the forofitos selected to realize the sampling had to fulfill certain characteristics like a DAP ≥ 20 cm, an inclination no greater than 20 ° and an exhibition to the rays of the sun for the growth of the lichen. In this way, the determination of air quality was achieved through the calculation of the atmospheric purity index (IPA) and the environmental classification factor (FCA). According to the lichen species found in the sampling sites, a taxonomic list of specific species was achieved through the observation and analysis of their morphological characteristics. Ultimately, through the conduct of this research it was possible to demonstrate that lichens are a great alternative for the arrest of air pollution, that in a simple and ecological way you can indicate the degree of affectation in which an area such as It was observed in the studied areas where the influence of high vehicular and industrial flow reduced the presence of lichens, established as bioindicators because of their sensitivity to air pollution.