In order to study statistical properties of surface fluctuation in a Wolf-Villain(WV) model。maximal-and minimal-heigIlt distributions(MAHD and MIHD) of saturated surfaces in a(1+1)-dimensional WV model are investigated with theory of extreme value statistics.It shows that both MAHD and MIHD csn be fitted well with universal functions of different system sizes.They are asymmetrical.MAHD takes on a generalized Fisher-Tippett-Gumbel(FTG) distribution,a typical extreme value distribution function.MIHD,however,displays a slightly different distribution,a modified FTG distribution.

Roughness distributions of 1+1 dimensional noisy Kuramoto-Sivashinsky(KS) equation at steady states are obtained and compared with Kardar-Parisi-Zhang(KPZ) equation's with numerical simulation.It is shown that the scaling functions of roughness distributions of the noise KS equation in 1+1 dimensions show small finite-size effects.They are in good agreement with the Kardar-Parisi-Zhang(KPZ) equation's.