Abstract: Through studying the wave solutions of the non-linear equations of the two-dimensional quasi-momentum non-divergent and non-frictional atmosphere, it is demonstrated that the characteristics of the nonlinear wave solution is determined by the sign of parameter b.If b >0, the solution is periodic and period is the same as that of the linear solution. If b≤0,the solution is solitary wave. The analytical expression of the wave solution is given in this paper. It is found that the solitary waves in the unstablely and neutrally stratified atmosphere have structures similiar to the squall line. The distribution characteristics of the physical variables are given.