Our research focus on eight locations: Kaohsiung Cijin, Taichung Port, Tamsui Bali, Yilan Wushi Fishing Harbor, Dapeng Bay, Golden Coast, Penghu Dachi, and Green Island to analyze coastal topography in Taiwan. After capturing the aerial photographs, we used Image J to calculate the area and analyzed possible causes of change. Because of typhoons, sediment load and littoral drif, the eight targets in the research show that area increase gradually in the trend of stable linear relation except Dapeng Bay. The trend about areal change in Dapeng Bay is decreasing because the erosion gradually approaches the accumulation. Taiwan is surrounded by the sea, and we set many breakwaters to prevent coastal erosion. The research aims to analyze short-term changes in coastal areas, and the results indeed indicate that breakwaters prevent the coastline from receding or even expanding. However, sands can’t be created out of nothing, the chain of effects caused by man-made structures prompt us to deep thought.