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Chitosan is a biopolymer derived from chitin and the most abundant polysaccharide in nature after cellulose. This biopolymer has been applied in different areas due its biodegradability and biocompatibility properties. Modifications of chitosan structure by cross-linking chemical agents can alter its physical, chemical, and morphological characteristics. The present work aimed at studying the structural characteristics of chitosan/polyvinyl alcohol (PVA) spheres cross-linked with glutaraldehyde submitted to oven-drying and freeze-drying processes. The thermal-treated of spheres and chitosan (control sample) were analyzed by XRD, SEM and FTIR techniques. Multivariate statistical analysis, PCA, was applied to samples IR spectra. According to results, the freeze-dried spheres showed a smaller crystal size (6.032 nm), while the oven-dried spheres presented a smaller crystalline phase (3.49%). MEV images have encompassed the different surfaces of the manufactured spheres as a result of drying methods. Slight chemical changes were observed in the IR spectra from the cross-linked spheres. In addition, PCA has revealed different clusters referred to the structural modifications. Therefore, the increasing of openness and receptivity for chemical reactions, as well as the adsorption capacity, could enable different applications of the chitosan, mainly the adsorption properties to remove residues and for water treatment.