In this study, the morphological changes of chemically treated (or preserved) with aqueous solutions of 1) a sodium chloride (NaCl) and 2) a compound containing sodium silicate, so called “wasserglass”, and untreated I-type collagen fibers of Mongolian goatskin are investigated by atomic force microscopy in ambient condition and at room temperature. The experimental results show that the difference between D period for both chemically treated and untreated collagen fibers are a relatively stable for morphological behavior. However, we find that the width of collagen fibers treated with the NaCl solution is more increasing with approximately 112 nm than those of samples (untreated and treated with wasserglass solution) for the range 93.4-94.8 nm. We also observe that a typically structure of the collagen fibers generally, a dense packing of the untreated and treated by wasserglass collagen fibers in bundles in a nearly parallel arrangement, with little changes in orientation can be seen. The collagen fibers treated by NaCl are a more destructive than untreated and treated by wasserglass for collagen fibers.