Abstract: Study of birds has great importance in the discipline of Ecology. Environmental pollution, climate change, depleting food resources and overuse of pesticides causes the declining of population of birds species. The present investigation is undertaken to enlist the species of birds particularly Passerine birds as well as causes of its declining. Investigation was carried out for two years from 2012 to 2013. 25 species of passerine birds were observed and causes of their declining were studied in jurisdiction of the research area – Painganga sanctuary .Of these all 25 species were found to be declined to certain extent. The most declining species was found to be Ploceus Philippines ( Baya Weaver) while the least decline species was found to be Pscittaceula kramery (Rows ring parakeet). Pesticides used in the vicinity of research area particularly in the agricultural fields were Acephate, alachlor , Atrazine, Benomyl, Bifenthrin, Captan, Chlorothalonil, Cypermenthrin, Dichlorvos, Diclofop Methyl, Decofol, Mancozeb, Methomyl, Metolachlor, Oxadiazon, Oxyflourfen, Permethrin, Phosphamidon, Propiconazole, Propoxur, Thiodicarb, Thiophanate Methyl, Triadimefon, Trifluralin. From the above investigation it could be concluded that climate change, depletion in food resources and overuse of pesticides were found to be the cause of decline. [A. N. Jadhao (2014). Study of Effects of Some Factors on Declining of Some Passerine Birds in Painganga Sanctuary of Umarkhed, Dist. Yavatmal M.S., Proceeding of National Conference on Renewable Energy and Environment, India, Sept. 2014] ${imageDescription} Comment