Abstract: This paper discusses the optimum methods for calculating and determining various hydraulic parameters and mud rheologic parameters in jet drilling.The Sp-hydraulic optimization slide rule can bc used in calculating and determining the proper relationship of hydraulic parameters and mud rheologic parameters.It includes:Side 1(1)rheology of drilling mud,such as n,k₂,θ₀θ₃₀₀,θ₆₀₀,etc.(2)critical velocity and "Z" value,(3)rheological model₃-modified power law or power law,(4)lifting capacity,(5)pressure losses in laminar flow,Side 2(6)pressure losses in turbulent flow,(7)bit hydraulic optimization