Monte Carlo simulation studies are performed to examine the effects of amorphous surfaces and the size of the system on magnetic critical properties of a face-centered cubic magnet modeled with a Heisenberg Hamiltonian. A Gaussian probability distribution of the exchange integrals is applied for the description of amorphous surfaces. The Spontaneous magnetization and magnetic susceptibility are calculated for both the inner and surface. A variety of phase diagrams have been also obtained. The simulated results can well explain the experimental facts.