Abstract:Pallas isogene lines possessing known barley powdery mildew (Blumeria graminis f.sp.hordei) resistant genes were used in virulence analysis for the population consisted of 729 isolates collected from the Winter Barley Region of China in 2005 and 2006, and more, resistance and resistance genes to powdery mildew in 328 barley varieties (lines) were identified. All isolates were avirulent to Mla1 Mla(A12), Mla3, Mla6 Mla14,Mla7 Mla(No3), Mla7 Ml(Lg2), Mla9 Mlk, Mla9,Mla13 MlaRu3, Mlp1, Mlg(Cp) and mlo5, and the frequencies of isolates overcoming the genes Mla12 MlaEm2 (0.1%), Mla7 Mlk (0.4%), Mlat Mla8 (0.9%), Mla10 MlaDu2 (2.8%) and Mlk1 (4.2%) were very low. Twenty-one pathotypes were found from the examined populations, and pathotypes 000, 001 and 003 were dominant. Almost all of 328 varieties (lines) tested were susceptible to powdery mildew, but 37 of these were resistant to all dominant pathotypes. Resistance genes can be postulated in less of the varieties (lines) investigated positively, the resistance genes, included in these varieties (lines) were Ml(Bw) Mla8, Mlg, Mlra Mla8, Mla9 Mlk, Mla1 Mla(A12) and mlo5.