This study conducted a comparative study between groin and T-groin. The study was done by developing stable coastline equation between groins and between T-Head groins. Stable coastline equation is the follow up of previous research by the same researcher. Meanwhile, stable equilibrium coastline equation between T-Head groins is the development of stable coastline between groins equations. Comparation study in erosion on the downstream groin and the maximum erosion shows that T-groin provides better coastal protection than groin.