Abstract: Salawati Basin is located in the Bird Head region of eastern Indonesia. It is an important petroliferous basin in Indonesia. Based on the study of regional geological data, combined with seismic and log data as well as oil/gas fi eld data, the characteristics of petroleum geology and oil/gas distribution as well as main factors of hydrocarbon accumulation were researched. It showed that Salawati Basin underwent three stages as the early rifted stage, the middle compressional sag stage and the late compressional folding including local thrust stage. The source of Salawati Basin is the marine shale of Klasafet Formation in Miocene and the reservoir is the carbonate reef of the Kais Formation in Miocene. The Kais Formation underwent three stages and the platform carbonate developed in the fi rst stage is the good oil and gas migration path. Three fairways exist in Salawati Basin. The distribution of oil and gas fi elds is controlled by hydrocarbon differential accumulation. It features in gas inside and oil outside on the plane. The key factor of hydrocarbon accumulation is the NW-SE trend of structural nose dipped into the kitchen in the northwest of the Basin. Meanwhile, the KOI area located in the structural nose is the future exploration target