Forests constitute the largest ecosystem and habitat of valuable species of plants and animals on the earth surface. The increasing size of population combined with increasing diversity of human activities is continuously degrading the forest areas of the earth's surface causing great threat to it in respect of shrinkage of coverage, loss of biodiversity and disturbance in the ecological balance. The intense depletion of forest cover in various parts has also brought about large-scale environmental changes including disappearance of many valuable floral and faunal species. In the said context, the district of Goalpara, located in the western part of Assam, was dominantly covered with dense Sal (Shorea Robusta) forest, widely distributed in both the lowland and hills of the district. However, during last few decades the dense Sal forests of the district have experienced massive depletion because of excessive exploitations and encroachments transforming many patches of forestland treeless and now being used for other purposes. Even the reserved forests are also under acute degradation and encroachment. In this paper, an attempt is made to explore the nature and dimension of forest cover change alongside massive encroachments and associated implications in Gonbina Reserved Forest of Goalpara district, Assam during 1977-2010, with the help of Survey of India toposheet, satellite imagery, field survey and Geographical Information System.