Diversity of archaeal was studied in deep-sea sediments from the Western Pacific by PCR-RFLP and sequence analysis of 16S rDNA and comparing with the published sequences in GenBank data-base. Archaeal 16S rDNA sequences were within phylums of Crenarchaeota and Euryarchaeota, respectively. The majority of archaeal phylotypes were Marine Benthic Group B (MBGB), Marine Benthic Group D (MBGD) and Marine Crenarchaeotic Group (MCG).Additional sequences grouped with the South African Gold Mine Euryarchaeotic Group (SAGMEG)、Deep-Sea Hydrothermal Vent Euryarchaeotic Group (DHVEG)、UCIIB、VALIII and Marine Benthic Group E (MBGE). These results indicate that archaea are abundant and diversified in surface environment of subseafloor sediments.