Abstract: The discovery of Cambrian hydrocarbon source rocks on the southern margin of the North China block provides a new gas horizon,a new distribution area,and a new research field for finding subsurface energy resources in North China.It is conductive to initiating a new situation for gas explo-ration in North China in the21st century.Comprehensive analysis reveals that deep-sourced gas and py-rolysis gas may have formed and early-formed gas may have been preserved on the southern margin of the North China block.