Abstract: Chuxiong basin in Yunnan province is a long-term developing and superimposed petroliferous basin with multi-deposits of marinefacies, continental-marine interaction facies and continental facies. There exist translithospheric fracture, lithospheric fracture, crustalfracture, basement fracture and caprock fracture within and around the basin. They prov ide favorable passages for oil and gas migration. Thestudy shows that it has well conditions in petroleum geology for forming a multi-superposition petroleum system with biogenetic and non-biogenetic origins and multiple types of traps dominated by anticline as well as good preservation in late period of the basin. It is concludedthat it is a medium-scale petroliferous basin with very rich hydrocarbon resources.

Key words: Yunnan, Chuxiong basin, origin, fracture