Evolutional characteristics of forest landscape structure and its internal driving mechanisms in Jinzhai County, Eastren Anhui Province from 1985 to 2011 were studied by taking TM images of 1986, 1996 and 2011 as data sources and using landscape indices analysis based on GIS and RS technology. Results showed that Jinzhai's woodland area continued to grow, arable land continued to decrease, and other landscape types increased or decreased by different amplitudes in the past 25 years. From 1986 to 1996, patch density, fractal dimension and Shannon evenness index changed negatively, the speed of landscape heterogeneity accelerated, and landscape pattern was in the severe situation of complex and fragmentation. From 1996 to 2011, after the "Grain for Green" project, the indicators changed positively, the situation of landscape fragmentation was effectively curbed, and landscape pattern turned to equalization and regularization. As a result, landscape structure has been optimized obviously. Natural geographical environment and the implementation of the "Grain for Green" project are the main driving forces for the formation of the evolutional characteristics of forest landscape pattern.