Southern Sichuan city group is one of the four city groups in Cheng-Yu economic zone. Most of cites are constructed in hill and beyond the rivers. The limited developing space force cutting slope and backfill in the city construction activities frequently. Lots of problems are triggered along with the city development. Seismic activity, red-bed weathering and geological hazard are the major problems of environmental engineering geology in southern Sichuan city group. Huayingshan fault and Yingjing- Mabian-Yanjin fault are strongly active in this area. Jurassic and Cretaceous red-bed mudstones are of fast weathering. The red-bed slope has six failure types, including weathering spalling, rockfall, collapse, topsoil slip, slump and shallow landslide. Landslide and rockfall are the major geological hazards in southern Sichuan city group, the distribution density reach to 7.81 per one hundred square kilometers.