In this article, the structure of the cotton fiber stored in the riot was observed with an electron microscope, and as a result, it was found that the location of the fibrils in the primary and secondary layers was different. Analysis of the research results showed that the number of microorganisms and fungi increases due to an increase in density in the lower layer of the riot. In the proposed version, that is, the quality of the fibers practically does not change with a decrease in the density value in a small-sized bundle.