Abstract: Whether there is drilling failure in oil/gas exploration is a controversial topic. This paper preliminarily defi nes successful well and failed well from different aspects and different angles of oil/gas exploration. Currently well location arrangement of oil/gas exploration and development is mainly based on seismic exploration results. Seismic exploration is a predicative science, and it is normal that there are both success and failure in well arrangement. Anticline trap is the major target of mountainous seismic exploration. Seismic exploration consists of three aspects, i.e. acquisition, processing and interpretation, and deviation in each aspect may result in drilling failure. Poor quality of acquired data may lead to multiple solutions of processing and interpretation, thus causing lower precision of seismic results. Improper processing parameters may result in false structural appearance and mislead interpreters to make wrong decisions. Complex mountainous structure interpretation may cause deviation of horizon calibration, structural modeling and velocity fi eld, resulting in well-to-seismic incoincidence. Analysis on drilling failure means that interpreters timely acquire geologic and log data of drilled wells, use seismic techniques to confi rm or correct original results, then carry out corresponding seismic exploration techniques and measures to acquire new seismic results, timely guide drilling work of next step, and maximize oil/gas exploration benefi t.