Abstract:Many secondary mountain hazards have been direct induced or indirect induced by the Wenchuan earthquake on May the 12th, 2008.Not only in terms of the types, number, size of the secondary mountain hazards but also from the impact of them to the mankind’s “natural society economy” complex systems, the mountain hazards which induced by the Wenchuan earthquake are great and rare all over the world.At the same time, because of the excitation and mutual transformation between various types of the secondary mountain hazards,such disaster chains (nets) as “collapse landslides”,“collapse barrier lakes”,“collapse landslides debris flows” have been formed.In this paper,the forms,development characteristics and causes of Wenchuan quake induced secondary mountain disaster chains (networks) were preliminary analyzed.The development processes of the above mentioned three major disaster chains were described.Four laws which have behaved in the disaster process of the disaster chains were summed up. The development causes of the Wenchuan earthquake disaster Chains (nets) were briefly analyzed from natural factors and human factors.