The paper presents the application of parameter analysis to figure out how to design the piston in an electromagnetic tubular pump in order to increase the electromagnetic force. Based on the patent [1], the discussed tubular pump has a tube body wound eight separated coil sets to drive an inner piston. The piston has a permanent magnetic ring and therefore reciprocates within the tube to thrust liquid. In order to increase the electromagnetic force, the key how to design the piston is to design the permanent magnetic ring. Parameter analysis is a conceptual method of repeating three steps: parameter identification, creative synthesis and evaluation. Due to simple structure of the piston, we only repeat the latter two steps after having identified three key design parameters: magnetic ring thickness, tube-end gap axial length and the distance between magnetic ring and a coil set. The commercial software ANSYS, a finite element analysis tool, is chosen to evaluate static electromagnetic fields. Through the application, some determinate design directions have been concluded and are helpful increasing electromagnetic force of the electromagnetic tubular pump. Some experiments should be done in the future for testing the proposed conclusions.