In this paper we consider a class of semilinear systems of partial differential equations of higher order A(t)u1+(-1)MuxZM=f(u), which contain a class of the nonlinear Schr?dinger equations, where the matrix A(t) is nonsingular, nonnegative definite and f(u) satisfy the conditions (i) f(u) = -grad F(u), F(u)≥0(ii) (g(u),u)≤α(u,u) + b, g = A-1f. The existence, uniqueness and regularity of solutions for periodic boundary problems and Cauchy problems in global are proved. |