Abstract: The equation of pattern formation induced by buoyancy or by surface tension gradient in thin layer is considered,the equation confined between horizontal poor heat conductors is introduced by Knobloch (1990) ∂u/∂t=αu-μ∇2u-∇4u+K∇·(|∇u|2∇u+β∇2u∇u-γu∇u+δ∇|∇u|2), where u is the planform function,μ is the scaled Raifleigh number,K =1 and α represents the effects of a heat transfer finite Biot number.The β,δ and γ represent the boundary condition at top and bottom or non Boussinesg effects respectively.The Knobloch equation with α0,μ0,β=δ=0(the boundary condition at top and bottom is the same) is considered,the local existence,global existence in the L2(Ω)-space and the global attractor have been obtained respectively.