A whole slide of a loosen and accumulated collapsing earth slope bursts out in Tufengyan-Majiaba of Zigui County in Yangtze Three Gorges on July 16th, 1986. The slide belongs to an especially large landslide of wiggling type with rainstorm. Under the restraining of two gullies which extends southnorth direction, the plane shape of the landslide appears as a long bag pattern along eastwest direction with 250-500m long and 2,400m wide and the area is about 1 km~2, the volume about 30 million cubic metres. Part of the landslide have been moving wigglely downward and changing its form, if these parts fall into Luogudong River, they will pile up a dangerous earthrock dam and if the dam cracks, the life and the property of the inhabitants who live in lower reaches of the river would be endangered. So, drainage and monitoring and forecast must be taken into full account around the landslide in order to take precaution against accidents.