Reactor systems with lead-bismuth eutectic (LBE) as coolant are increasingly getting more research interest in recent years. In this paper, a theoretical analysis of the steady-state natural circulation characteristics of LBE is carried out. The relation between the mass flow rate m˙ and the heating power Q is given by m˙=(KfQ)1/c. And the relation between the inlet-outlet temperature difference ΔT and wall-to-fluid temperature difference within the heating section ΔTh is given by ΔT=(KtΔTh)d. The determination methods and influencing factors of Kf and Kt are studied. Through theoretical analysis, the natural circulation with LBE as a working substance has higher mass flow, temperature difference between the inlet and outlet of the heating section and loop pressure loss than the natural circulation of water or sodium under normal working conditions. And the LBE natural circulation is more sensitive to changes in heating power. Moreover, steady-state and transient experimental studies have been performed in an LBE Natural Circulation test loop (LNC). A one-dimensional thermal-hydraulic system code FRTAC is preliminarily validated against test data and utilized to study the natural circulation characteristics of LBE.