FePd alloy films with different thickness have been prepared by DC magnetron sputtering on glass. The effect of thin film thickness on the structural and magnetic properties was investigated. The results indicate that the ordering process in the thin FePd alloy film occurs in the thicker ones. In-plane coercivity value first increases rapidly as thickness increases from d=22.5 to 67.5 nm, and then the value decreases with further increasing film thickness. A peak value of coercivity～3200Oe appears at d=67.5 nm.