This article presents a spectral analysis of wave uplift loads on a horizontal deck.The wave uplift force spectrum on the underside of the deck is obtained.It is shown that the wave uplift force spectral density decreases with the increase of the relative clearance Δh/H1/3.The influences of different incident wave parameters,including the relative wave height H1/3/d,the relative deck width B/Ls and the relative clearance Δh/H1/3 on the dimensionless zeroth spectral moment of the uplift forces are discussed.It is found that the zeroth spectral moment of the uplift forces increases with the increase of the relative wave height H1/3/d,and decreases with the increase of the relative clearance Δh/H1/3.A new dimensionless prediction model for the zeroth spectral moment of wave uplift loads on the deck is proposed and the relationship between the wave uplift forces and the zeroth spectral moment of the uplift force are obtained.