We study the onmidirectional reflection bands (ORBs) of one-dimensional magnetic photonic crystals. We show that the ORB is a general property of a one-dimensional magnetic photonic crystal consisting of two alternating layers with different wave impedance and the same index of refraction from the analytical expressions for the edge frequencies of omnidirectional reflection bands. We also derive the analytical expressions for equiomnidirectional contours of the omnidirectional reflection bands. These analytical expressions give the physical insights on the properties of a real finite array as well as the design parameters for device applications.