Systematic study of the geological conditions and processes of hydrocarbon accumulations in Qaidam basin shows that there were six main factors controlling hydrocarbon accumulations. (1) Hydrocarbon generating sag controlled the distribution pattern of oil and gas. (2) Reservoir quality influenced the formation of oil and gas reservoirs. (3) Abnormal hydrodynamic field controlled the migration and accumulation of hydrocarbons. (4) Faults in source rocks controlled the formation of oil and gas reservoirs. (5) Middle and late Himalayan movements determined the formation and development of structural traps. (6) Occurrence of trap belts determined the specific distribution of pools.