Abstract: Dynamics of green macroalgae early development and aggregation in the northern Jiangsu Shoal-water region were simulated using survey data and the FVCOM ocean model for April 2012. The results indicated that in 2012, green macroalgae initially bloomed along the Qidong coast of Nantong, concentrated in the Sun Island region around Xiaoyangkou. This region is one of the primary sources for early blooms of green macroalgae with gradual expansion northward and toward the open seas. The coastal area around the Lvsi harbor does not serve as a center of origin for early blooms of green macroalgae. The survey found that most of the green macroalgae was gathered near the grooves of the radial sand ridge. Due to tidal impacts, the early onset of green macroalgae accumulation is consistent with the radial sand ridge to radial banded, or patch-shaped, distribution. The combination of tides and frontal upwelling of northern Jiangsu Shoal-water in the Yellow Sea was a major factor in inducing green macroalgae blooms.