We study large time asymptotic behavior of solutions to the periodic problem for the nonlinear Burgers type equation $$ \left\{ \begin{array}{l} \psi_{t}=\psi_{xx}+\lambda \psi +\psi \psi_{x},\quad x\in \Omega, \quad t >0 , \\ \psi (0,x)=\widetilde{\psi}(x), \quad x\in \Omega, \end{array} \right. $$ where Ω = [−π, π], λ < 1. We prove that if the initial data $${\widetilde{\psi}\in {\bf L}^{2}(\Omega)}$$ , then there exists a unique solution $${\psi (t,x) \in {\bf C}\left( [ 0,\infty ) ;{\bf L}^{2}(\Omega) \right) \cap {\bf C}^{\infty }\left( ( 0,\infty ) \times {\bf R}\right)}$$ of the periodic problem. Moreover, under some additional conditions we find the asymptotic expansion for the solutions.