The statics relation of the Stewart platform has been investigated from the viewpoint of the forward/inverse force transmission capabilities. Two eigenvalue problems corresponding to the forward and inverse force transmission analyses have been formulated. The forward force transmission analysis is to determine the magnitude bounds of the force and moment generated at the end-effector for the given magnitude of actuating forces. Conversely, the inverse force transmission analysis is to find the magnitude bound of actuating forces for the given magnitudes of the force and moment at the end-effector. The inverse force transmission analysis is important since it can provide a designer with valuable information about how to choose the linear actuators. It has been proved that the two eigenvalue problems have a reciprocal relation with each other, which implies that solving either of the eigenvalue problems may complete the forward and inverse force transmission analyses. A numerical example is also presented.