One of priority pollutants of the environment of Yerevan – Armenia’s capital city – are chlorine-containing compounds. Such pollutants originate mainly from scientific and industrial enterprise (SIE) “Nairit” located in the bounds of the city, and manufacturing synthetic rubber and chlorine-containing compounds. Plants are effective indicator of assessment of pollution level of a locality and atmosphere cleaning phytofilters. The research goal was studying dynamic changes in chlorine contents in tree species growing in Yerevan area. The research was done in 2005 through 2015. All samples were collected and treated through the accepted methods. Chlorine contents were determined in water soil extraction following ISO 11464 standard, and in plants – through the method of titration with Ag (NO3). A schematic maps of chlorine concentration in soil and vegetation were produced using a basic digitalized topographic map (1:10000) and ArcGIS software. The generated data credibility verified by Quality Control Charts. Studies covered regularities of element accumulation and dynamic changes in leaves of different tree species and soil. Studied were absorptive and accumulative properties of different tree species in respect of the element and tree species having high indication and phytofiltration potential, identified. Based on data obtained, schematic maps of chlorine pollution of plants were produced which then helped isolate severely polluted areas. Ecologically tolerant species with high phytofiltration potential identified in the result of our research are recommended for use with a view to reduce levels of chlorine pollution of urban environment.