In India, 49 million hectares area is affected by soil acidity, of which 25 million hectares have pH below 5.5. More than 90% area in north-eastern region of the country is affected by soil acidity. This particular abiotic stress limits the expansion of area under agricultural crops and their productivity in this region. The degree of loss in crop productivity varies with varying degreee of soil acidity. Such problematic soils have geerally been degraded naturally and characterized by low fertility, low pH, toxicities of aluminium and manganese and low availability of nutrients viz., phosphorus, calcium, magnesium and potassium etc. These naturally degraded infertile acidic soils remain the principal factor limiting productivity and production of major crops in India. Acidity in the surface soil can be ameliorated with liming, but subsoil acidity is a serious constraint to plant growth because it can not be easily ameliorated with surface application of lime. Therefore, other management options need to be employed for improving productivity of these lands in order to help innumerable small farmers of our country. The book comprises eight chapters including overview of problems of acidic soils in India, toxic effects of aluminium, mechanisms, physiolgical and biochemical parameters, screening techniques, genetics and conventinal breeding, molecular approaches and genetic engineering for aluminium tolerance. Such information will definitely help to researchers and students working in this aspect.