Since the restriction of uncontrolled sand mining in the main stream of Yangtze River, a large number of sand dredging vessels have been flooded into Poyang Lake area, resulting in obvious changes in the morphology and landscape of the aquatic terrestrial ecotone. Human activities have profoundly affected the stability of the aquatic terrestrial ecotone of Poyang Lake. Based on Landsat TM/OLI remote sensing image data, the impact of sand mining activities on the morphology and landscape pattern of the aquatic terrestrial ecotone of Poyang Lake was measured quantitatively. The results showed that (1) the transformation between grassland and mudflat was the most frequent. The fluctuation of water area decreased and the scope of the aquatic terrestrial ecotone expanded. (2)The eastern and western shorelines were eroded, and the shoreline in the center of the lake was rapidly shrinking. (3)The shape of the aquatic terrestrial ecotone of Poyang Lake has simplified gradually, while the complexity of the shape of the river entry channel has increased, and its geometry has become irregular. (4)At the level of landscape types, the fragmentation degree of the mudflat landscape was the largest and its shape was the most complex. The fragmentation degree and shape complexity of farmland was the smallest and its agglomeration was the strongest. The connectivity of grassland was the best. The landscape index of sandy land had the largest change in magnitude. (5)The fragmentation degree of the aquatic terrestrial ecotone of Poyang Lake gradually decreased, the shape became increasingly complex, the landscape diversity decreased, and the overall connectivity and agglomeration increased. (6) The scale of sand mining was negatively correlated with the shape index of the aquatic terrestrial ecotone of Poyang Lake, and positively correlated with the landscape shape index and the shape index of the river entry channel, all of which passed the significant test.