Abstract
We investigate the Berry phase of a spin system in a q-deformed magnetic field. The Berry phase depends on parameter q and which causes the deformation of the Berry phase. When q not equal 1, the parameter space for the spin-half particles in magnetic field is deformed and immovable at the point of phi = 0, pi/2, pi. The same Hamiltonian can also be constructed by q-deformed Lie-algebra and magnetic field.