This study on the direction, pathway and phase of oil/gas migration in the Lunnan area is based on the crosscutting relation of fissure, fault and rock sequence in the cores of drillhole (successful and unsuccessful) and the analysis of minerals and theirs inclusions near linking sand, fault and unconformity. The result suggests that there were three phases of large-scale oil/gas migration and accumulation, and unconformities served as the main horizontal pathways and high-angle faults and fissures were the main vertical pathways. The first phase occurred mainly in the Hercynian, the second in 14~17 Ma and the third in the last 5 Ma. The first phase of migration, mainly horizontal, were from the southwest and south to the north of the Tabei uplift and the later two phases, mainly vertical, from the southwest and south to the north and from east to west.