The catastrophic debris flow disaster occurred in Zhouqu County in August 8

2010 caused greatcasualty and property damage. Survey

empirical analysis and inductive inference were made to investigatethe causes of the Zhouqu debris flow disaster by analyzing the geological conditions of the debris flow. Two main causes were the natural factors like mountain collapse by earthquake

strong rainstorm suddenly oc-curred in a particular place and antecedent severe drought

and the human factors like disordered exploita-tion

poor flood control engineering quality and unreasonable urban development planning.Thus

the deep causes were derived

i.e.

the lacks of the environmental evaluation

early warning system and mechanisms for disasters

and consciousness for preventing and reducing disasters.The measures for prevention are put forward

i.e.

early warning

accurate monitoring and rescuing emergency. The establishment of the com-prehensive system of early warning and prevention may fundamentally prevent the recurrence of similar geo-logic hazards.