The present research has been carried out as a preliminary survey for an extensive research project to get scientific data for reconstructing the process of ethnogenesis of polynesians at the initial stage of settlement in the polynesia proper, which is scheduled to start in 1993. The main purpose has been to arrange as many things as possible for the excavation activities in 1993, 1994 and 1995, in Mangaia Island in the Cook islands as well as in the northern part of Viti Levu in Fiji. In Mangaia we carried out a test excavation at the Vairorongo archaeological site which is situated inside the makatea (reised coral reef) of the island, aiming at collection carbon-dating materials and at the evaluation of the wideness, extent and period of the site, of the quantity of human skeletal remains, faunal remains and artefacts embedded. We found the following collection through the test excavation, that is, human skeletal remains for some 30 individuals, about 500 stone tool fragments, some 300 pieces of shell artefacts, some 50 pieces of bone artefacts, about five kilogram of faunal remains, some 20 charcoal samples for dating, and soon. At the present stage, the findings obtained must be one of the biggest collections that have been ecxavated around the area of the central part of South Pacific, so that the site should be considered very promissing for a full-scale excavation in the future. It is very possible that an enormous amount of human skeletal remains, namely for 500 individuals or more, is embedded to be excavated at the site. In Fuji we conducted a general survey around the Rakiraki district looking for archeological sites, and as a result, we found a very good site at the Nanuakoto islands in the district, the site probably dating back to some transition time between the Lapita and early Fijian periods. So we have decided provisionally that the site site should be an excellent candidate to excavate in the research project in 1993 to 1995.