Abstract: A set of new formula to calculate spherical swashplate axial piston pump kinematics parameters,such as: displacement,velocity and acceleration,was deduced from coordinates method.The analysis method and deduction procedure ensure the preciseness of the formula in theory.Applying above new formula and current calculation method to the same aero-engine fuel piston pump,the results show that owing to the use of linearization,the currently calculated displacement and velocity errors are less than 0.4 percent,but the maximum acceleration error reaches 3.34 percent.Compared with current calculation method,the new formula is precise and simple,providing a theoretical basis for calculation of kinematics parameters of this type of piston pump.