Objective : Ancestral qi and vitality qi are the most significant qi in lung and heart. However, the origins and functions of those qi are not quite detailed somehow. Method : I will try to find out the origins and functions of ancestral qi and vitality qi through "Hwangdineijing". Result : The ancestral qi is the essence of lung and the vitality qi is the essence of heart. Conclusion : The function of ancestral qi is what puts nutrient qi and defence qi into meridians to make them being rightways of meridians and those of vitality qi is what pushes ahead nutrient qi and defence qi through meridians.