Abstract: In 2002, PetroChina purchased the assets of Devon Energy Company in Indonesia, and started the operation of PetroChina Contract Blocks in Indonesia. Petroleum play analysis made new hydrocarbon-bearing formation discovered in the west part of the Jabung Block. New exploration interval and potential have been increased because of new commercial discovery. There are significant discoveries in the Bangko Block on the basis of analysis of trap types and their formation time. This achievement laid a foundation of remaining this block. CNPC will havemore interests to discover oil fields because that one of these partners had not take part in drilling West Piano-1 and Gambang-3. A series of reefs and structure traps have been found in the Salawati Island Block on the basis of comprehensive analysis of reservoir inversion and oil-gas check-up study, which resulted in a series of discoveries by drilling. Since 2003, PetroChina International Company in Indonesia has fixed 27 exploration-well locations on the basis of integrated research of petroleum geology and seismic-data particular interpretation. Up to the end of February 2005, 19 exploration wells have been drilled, 13 wells of which got discoveries, and successes of the exploration efforts have been achieved