Abstract: Based on the wave-damping works in the experimental area for water quality improverment of Meiliangwan water source of Taihu Lake,wave-damping effects of five types of piles layout are compared in the wave model test with rectangular concrete piles.The pile layout of Scheme 2 is recommended.A modified transmission coefficient formula is derived based on the linear small amplitude wave theory,and calculation results are in good agreement with the test results.