To reduce the storing space and handling costs for hay/straw bales, recompressing the original bales after adequate hay drying is recommended. In this project, a recompression machine was designed, constructed and evaluated. Solidwork and Nastran software were employed to model, and to analyze the stresses in the components of the machine, respectively. The components of the machine consisted of baling chamber, ram and discharge chamber, designed as based on some physical and rheological properties of the hay/straw bales. The effect of compression levels (30, 40 and 50% strain) on the recovery length of the recompressed alfalfa/straw bales (in relaxation chamber) were investigated using a factorial experiment of a randomized complete block design. The effect of recompression level and crop type on length recovery of bales (in the relaxation chamber) was significant (P<0.01). The results showed that the recompressed alfalfa/straw bales of 50% reduction in initial length had the highest length recovery in the relaxation chamber. Therefore, to achieve a desired length reduction for hay/straw bales, it is recommended that an additional strain be applied during the recompression process in order to compensate for the expected length recovery.