Abstract: Paleomagnetic study of drilling cores in Nanniwan oil field shows that it is an effective way to obtain the orientation of drilling cores by picking up and aparting two paleomagnetic remnant components, the lower temperature component and the higher temperature component which were formed in different periods. The viscous remnant component (lower temperature component), which could be easily and concisely gotten in the NRM~150℃ demagnetization period, has been demonstrated to be a good and main factor for orientation. At the same time,the depositional remnant component(higher temperature component)could be easily influenced by many factors and could be a good auxiliary and verified tool for orientation of drilling cores.