Based on the meso-scale surface observations, the effect of zonal coastline, as an example, from Yangjiang to Dianbai, on local precipitation is analyzed. The results show that in summer, sea and land breeze circulation appears obviously under weak gradient wind condition. In the early morning, and from the afternoon to evening, the sea breeze front moves along the coast with the replacement of the sea and land breeze circulation, local precipitation could appear under certain conditions.