Physical and geometrical characteristics of fruits are the most important parameters in design of sorting systems. Among these characteristics, mass, outer dimensions, projected areas and volume are the most important ones in sorting systems. The size of fruit is frequently represented by its mass because it is relatively simple to measure. However, sorting based on some geometrical attributes may provide a more efficient method than mass sorting. Moreover, the mass of fruit can be easily estimated from geometrical attributes if the mass model of the fruit is known. Thus, modeling of fruit mass based on some geometrical attributes may be useful and applicable. Therefore, the main objective of this research book is to determine optimum mass model(s) based on some geometrical attributes for some important fruits, i.e. apricot, nectarine, peach and plum.