Sustainable agriculture has emerged as a key issue in agricultural development and natural resource management because of widespread and growing concern about the seriousness of degradation of the world's natural resource base and ever-increasing pressures on these resources from continuing rapid population growth. This paper examines the changes in land use and the problem of tropical deforestation affecting the world's land resource base for sustainable agricultural development. Global land-use changes have been slow in the last decade. However, changes in land-use patterns have been significant in many developing countries, especially the conversion of forest land into agricultural land to meet increasing demand for food and fibre. It is estimated that over 11 million ha of tropical forests are cleared every year in Latin America, Asia, Africa, and the Pacific Islands. The most serious consequence of tropical deforestation is soil erosion, which may greatly increase after forests are cleared. It is also apparent that tropical deforestation is contributing to global climate change. Improved agricultural sustainability, combined with policies to protect natural resources, is urgently needed to support the rapidly increasing population in developing countries.