The Wenchuan Earthquake have triggered many landslides and avalanches. Huge landslides buried valleys and created many gentle slope lands. The newly created lands are unstable and debris flow often occurs. Stabilization and development of the new lands is a new challenge. The second challenge is due to the damming of rivers and creation of quake lakes by landslides, which induces intensive fluvial process and may have long term effects on the river morphology. Many avalanche deposits consist of large stones without soil and fine sediment on the surface. Vegetation restoration on the avalanche deposits is the third challenge. These problems are studied based on field investigation and field experiments. Artificial step-pool system may stabilize the landslide body and control or mitigate debris flows in the incised gullies on the newly created land. The debris flow occurring in the earthquake area consists mainly of gravel, cobbles and boulders. They are two-phase debris flow rather than viscous debris flow although its specific weight is extremely high. The velocity of these debris flows is much smaller than that of the viscous debris flows because the collision of boulders and cobbles consumes a lot of energy. Quake lakes may develop into knickpoints, which will change the bed profile of the river and eventually stabilize the river. Planting Grimmia pilifera on the avalanche deposit can accelerate vegetation restoration and finally green the bared mountains.