The characteristic features of forming the collagen structure in the beam-house process and tanning have been investigated. It is shown that the moderate derma-swelling rate during liming provides effective fixation of the derma structure in tanning. The formation of strong cross-linkages during tanning leads to the change in the deformation character of derma collagen, especially in the compression test. The usage of the glutaric aldehyde by tanning allows to reduce the consumption of chrome compounds or fully exclude them and at the same time to receive soft elastic leather with a high volume yield.