The present investigation entitled 'Seasonal abundance and management of aphid, Rhopalosiphum maidis (Fitch) on barley, Hordeum vulgare Linn.' was carried out in Rabi, 2014-15 at Agronomy farm and in the laboratory of the Department of Entomology, S.K.N. College of Agriculture, Jobner (Rajasthan) with the objectives to study the seasonal abundance of aphid, Rhopalosiphum maidis (Fitch) and its natural enemies on barley, reactions of barley genotypes with aphid, the efficacy of insecticides and biopesticides against aphid and predatory potential of major coccinellid predator of aphid on barley crop.