The structure of the Reynolds stress in a turbulent flow over the multiple windbreaks of half‐circular sections across‐wind was investigated experimentally in the boundary layer wind tunnel. The quadrant analysis theory was applied to analyze the turbulent stress signals by partitioning the Reynolds stress into inward interaction, ejection, outward interaction, and sweep events in accordance with whichever quadrant the (u’, w‘)belongs to.u’ andw’ are the stream wise and transversewise velocity fluctuations, respectively The results show that whenZ/H <1,X/H <20, the sweep events are the largest contributors to the Reynolds stress followed by the ejection events while the inward and outward interactions are negative contributors.Zis the distance from the wall,Xis the downstream distance, andHis the height of windbreak. The stress contributions by sweeps and ejections are almost the same whenZ/H< 1,X/H >30.