As a pre-process of CFD (Computational Fluids Dynamics) analysis, mesh generation plays an important role in numerical simulation in the sense that mesh quality has significant influences on simulation results. For geometrically complex domains, quality structured mesh generation still remains a challenge. This paper presents a quality structured mesh generation process in a largescale complex domain along the Louisiana-Mississippi coast line, which is part of a numerical simulation and evaluation of coastal processes using the CCHE2D-Coast model. In this study, the study domain is about 440 km (longitude direction) x 320 km (latitude direction), and multiplescaled objects are required to be represented in detail, which makes it more difficult for quality structured mesh generation. The characteristic mesh size for the levees, roads and as-built hydraulic structures is 10-100 m, 10-100m for Pearl River, 100-1000m for Mississippi River, and 1000-2000m for the coast and gulf. To make the mesh lines conform to these objects as much as possible (which is desired for more accurate simulation), a multi-block scheme is used to decompose the whole domain into 17 blocks, and structured meshes with different resolutions was generated block by block. The assembled final mesh with 2103 x 1088 (= 2.288 M nodes) in this large complex domain was successfully generated using CCHE-MESH, a 2D mesh generator for both quality structured and unstructured meshes. Numerical simulation of coastal storm surge using the CCHE2D-Coast model based on this mesh produced satisfactory results.