Based on GIS,RS and the landscape analysis software,landscape changes in the middle and lower reaches of Houzhai River in Puding County of Guizhou Province from 1973 to 2004 were analyzed.The results indicated that paddy fields and dry fields held a dominant status.In the change of landscape types,forest land reduced continually,dry fields changed complicatedly,and the mutual transformation among grass land,shrub land and forest land was obvious.The area of bare rock increased remarkably in the slope range between 10° and 35°.Artificially 'returning cultivation land into forests and pastures','reclamation by damaging forests and pastures',and natural ecosystem converse succession existed at the same time.Therefore,the whole landscape was in an unstable state.
