To interrogate single-base resolution 6mA sites in the genome-wide, we develop DA-6mA-seq (DpnI-Assisted N6-methylAdenine sequencing), an optimized sequencing method taking advantage of restriction enzyme DpnI, which exclusively cleaves methylated adenine sites. We find DpnI also recognizes other sequence motifs besides the canonical GATC restriction sites, largely expanding the application range of this method. DA-6mA-seq requires less starting material and lower sequencing depth than previous methods, but achieves higher sensitivity, providing a good strategy to identify 6mA in large genome with a low abundance of 6mA. We rebuild the 6mA maps of Chlamydomonas by DA-6mA-seq and then apply this method to another two eukaryotic organisms, Plasmodium and Penicillium. Further analysis reveals most 6mA sites are symmetric at various sequence contexts, suggesting 6mA may function as a new heritable epigenetic mark in eukaryotes. Overall design: A new sequencing method is developed to detect 6mA in eukaryotes