The system damping and dynamic characteristics can be further improved by properly increasing the damping coefficient ζ h. For a special hydraulic damping structure, an arciform damping clearance often used in FCS, a mathematical model has been established for fluid flow using the theory of laminar flow in the clearance of parallel plates. Analytical calculations are made for fluid flow in the arciform clearance and relational expression is deduced for flow rate along the arciform cleaance height, pressure difference, maximum arciform clearance height, the flow rate for the fluid flow in arciform clearance as well, and its simplified formula is obtained by using the theory of hydrodynamics and the curve-fitting method. This paper consists of two sections:the first section focuses on the theoretical analysis by using the simplified mathematical model and the second section mainly describes experimental analysis. The simplified formula is corrected with experimental results by considerig various boundary conditions of the damping clearance. Experimental results show that this study of arciform damping clearance is reliable and practical. The system damping and dynamic characteristics can be further improved by properly increasing the damping coefficient ζ h. For a special hydraulic damping structure, an arciform damping clearance often used in FCS, a mathematical model has been established for fluid flow using the theory of laminar flow in the clearance of parallel plates. Analytical calculations are made for fluid flow in the arciform clearance and relational expression is deduced for flow rate along the arciform cleaance height, pressure difference, maximum arciform clearance height, the flow rate for the fluid flow in arciform clearance as well, and its simplified formula is obtained by using the theory of hydrodynamics and the curve-fitting method. This paper consists of two sections: the first section focuses on the theoretical analysis by using the simplified mathematical model and the second section mainly described experimental analysis. The simplified formula is corrected with experimental results by co nsiderig various boundary conditions of the damping clearance. Experimental results show that this study of arciform damping clearance is reliable and practical.