PetroChina has highlighted its resources strategy and spared no efforts to increase its oil and gas reserves since the 11th Five-Year Plan Period. The company has achieved a series of important results in large-scale hydrocarbon basins like Ordos Basin, Tarim Basin, Sichuan Basin, Junggar Basin, Songliao Basin, Qaidam Basin and Bohai Bay Basin, leading to a longest peak for reserves growth in PetroChina^’s history. Meanwhile, with the breakthroughs made continually in oil and gas exploration, PetroChina has also made an important progress in geological theories in the areas of marine carbonate rock, frontal thrust belt, large-area sandstone, volcanic rock, buried hill and its inner curtain oil and gas reservoirs, tight oil and gas, and shale gas, further enriching and developing China^’s petroleum geological theories. The study of exploration engineering technology has effectively promoted rapid development in this area. Development of geophysical acquisition, processing and interpretation technology, higher drilling rate for complicated zones and deep wells, logging appraisal technology, and horizontal well drilling technology including volumetric fracturing technology has shaped a series of technologies for exploration of different areas. The oil and gas exploration targets will be increasingly complicated and more diffi cult in the future. However, the development prospect for oil and gas exploration remains promising thanks to the progress in geological theories and exploration technologies.