DECREASE IN DNA METHYLATION 1 (DDM1) is the chromatin remodeling factor that has been genetically identified in Arabidopsis thaliana as a factor involved in the maintenance of repressive epigenomic modifications over transposons. In this study, we performed crosslinking mass spectrometry and biochemical analysis using reconstituted nucleosome to understand the chromatin remodeling activity of DDM1. We found that the unique C-terminal tail of heterochromain-specific H2A.W variant binds to DDM1. This result suggest that DDM1 functions with specific histone variants for the maintenance of repressive modifications and epigenetic regulation of transposon activity.