In this paper, we improve the extended trial equation method to construct the exact solutions
for nonlinear coupled system of partial differential equations in mathematical physics. We
use the extended trial equation method to find some different types of exact solutions such as the
Jacobi elliptic function solutions, soliton solutions, trigonometric function solutions and rational, ex-
act solutions to the nonlinear coupled Schrodinger Boussinesq equations when the balance number
is a positive integer. The performance of this method is reliable, effective and powerful for solving
more complicated nonlinear partial differential equations in mathematical physics. The balance num-
ber of this method is not constant as we have in other methods. This method allows us to construct
many new types of exact solutions. By using the Maple software package we show that all obtained
solutions satisfy the original partial differential equations