Khadivi-Khub, A. and Naderiboldaji, M. 2013. Predicting models for mass and volume of the sweet cherry (Prunus aviumL.) fruits based on some physical traits. Can. J. Plant Sci. 93: 831-838. There are instances when it is desirable to determine relationships among fruit physical attributes. For example, fruits are often graded on the basis of size and projected area, but it may be more economical to develop a machine which grades by mass or volume. Therefore, the relationships between mass/volume (either mass or volume) and other physical attributes of fruit are needed. In this study three Iranian cultivars (Mashhad, Siah Mashhad, Siah Daneshkadeh), of sweet cherry were selected and the various models for predicting mass/volume of sweet cherry from its dimensions, projected areas, and volume/mass were established. The models were divided into three classifications: (1) single and multiple variable regressions of sweet cherry dimensions, (2) single and multiple variable regressions of projected areas and (3) estimating sweet cherry mass/volume based on its volume/mass. Moreover, some physical characteristics, such as dimensional characteristics, true density, bulk density, and porosity were determined with common methods. Results revealed that mass modeling based on minor diameter, three projected areas, and the measured volume are the best models. The highest determination coefficient in all the models was obtained for mass modeling based on measured volume as R² = 0.93. At last, mass modeling from an economic standpoint was recommended as the most reliable modeling.