Following Jifazi landslide occurred in 1982 and Xintian landslide in 1985, a catastrophic landslide of Majiaba in Zigui County occurred on 16 July, 1986, about 7.5 km south of Yangtze River, being a complete revice of historic dormant landslide. Its revice was triggered by particularly heavy rainfall. The reactivated landslide attained a volume of 30 million m~3. Being due to damming gully by rock collapse at upper part of the slope, impounding water level in the gully rose rapidly, flooding emptied both-sidely into ancient slide deposits in a short time, creating a strong dynamic-statical water pressure, pushing ancient slide deposits on the middle-lower part of the slope to move downward till the valley. The gravity center of the gliding mass is higher now, there are many ruptures on the ground, both sides natural drains are filled by sliding deposits, therefore there must be a tendency of damming river. Taking continually monitor of slide movement, sliding, warning repairing drain system, transforming paddy fields into dry land, ramming ruptures on the ground can be taken as countermeasures.