The northern margin fault zone of Maxian Mt. in Lanzhou area is a Holocene active fault which includes about 4 secondary fault segments. Along the active fault zone, several palaeoearthquake events are found in trench profiles. The activities of palaeo-earthquakes exist inhomogeneity in time and space. In the east, on Maxian Mt. segment, there are two events occurred in 5 850 ±500 a B. P., 2 060 ±420 a B. P., respectively. Their magnitudes are about 7~7. 5, the recurrence interval is about 3 800 a.In middle segment, Qidaoliang segment, two events are ditermined, in 16 820 ±80 a B. P., 10 800 ±10 a B. P., both are in Late Pleistocene.In west segment, Xianshui valley segment in northern margin of Wusu Mt., one palaeo-earthquake with age of 1 245 ±560 a B. P. is found. Considering the distribution of loess landslides and ancient town sites, this event is mostly the Lanzhou M 7 in 1125. According to the palaeo-earthquake ages and recurrence interval features, the strong earthquake hazard segments of the northern margin active fault zone of Maxian Mt. will be the east segment Maxian Mt. fault segment and the west segment Xianshui valley fault segment of Wusu Mt..