The pathogens secrete effector proteins to establish a successful interaction and cause infection with their hosts.The functional characterization of effector proteins is the key to understanding pathogen pathogenicity mechanisms and plant disease resistance response.However, the functions of most candidate effector proteins (CSEPs) from barley powdery mildew (Blumeria graminis f.sp.Hordei, Bgh) have not yet been elucidated.Here, we cloned 101 CSEPs from barley powdery mildew, and 16 of which showed suppression of programmed cell death (PCD) induced by Bax or MEK2DD using Agrobacteria-mediated transient expression in N.benthamiana, while one of them could trigger cell death.Further single-cell transient gene expression assay indicated that some of the CSEPs that suppressed PCD also contributed to pathogenicity.To identify host targets of these effectors, we used some of the CSEPs as baits and performed yeast two-hybrid screening of a barley prey library constructed from mixed barley leaves and epidermal material that were infected with Bgh spores.We identified host target candidates that appear to be involved in host defense responses, carbon metabolism and plant growth, respectively.Further characterization of these effector-host target pairs will hopefully contribute to understand suppression mechanisms of B.graminis fungal pathogen.