The outbreak of severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) has caused an unprecedented pandemic. Since the first sequenced whole-genome of SARS-CoV-2 on January 2020, the identification of its genetic variants has become crucial in tracking and evaluating their spread across the globe.In this study, we compared 15,259 SARS-CoV-2 genomes isolated from 60 countries since the outbreak of this novel coronavirus with the first sequenced genome in Wuhan to quantify the evolutionary divergence of SARS-CoV-2. Thus, we compared the codon usage patterns, every two weeks, of 13 of SARS-CoV-2 genes encoding for the membrane protein (M), envelope (E), spike surface glycoprotein (S), nucleoprotein (N), non-structural 3C-like proteinase (3CLpro), ssRNA-binding protein (RBP), 2-O-ribose methyltransferase (OMT), endoRNase (RNase), helicase, RNA-dependent RNA polymerase (RdRp), Nsp7, Nsp8, and exonuclease ExoN.As a general rule, we find that SARS-CoV-2 genome tends to diverge over time by accumulating mutations on its genome and, specifically, on the coding sequences for proteins N and S. Interestingly, different patterns of codon usage were observed among these genes. Genes S, N sp7, N Sp8, tend to use a norrower set of synonymous codons that are better optimized to the human host. Conversely, genes E and M consistently use a broader set of synonymous codons, which does not vary with respect to the reference genome. We identified key SARS-CoV-2 genes (S, N , ExoN , RN ase, RdRp, N sp7 and N sp8) suggested to be causally implicated in the virus adaptation to the human host.pandemic had affected more than 190 countries and territories, with more than 5,731,956 confirmed cases and 353,854 deaths (https : //www.worldometers.inf o/coronavirus/).The size of the SARS-CoV2 genome is approximately 30 kb and its genomic structure is characteristic of that of known coronaviruses. SARS-CoV-2 genome is translated into two large overlapping polyproteins, ORF1a and ORF1ab. These polyproteins are cleaved into five structural structural proteins, including spike protein (S), membrane protein (M), envelope protein (E), nucleocapsid protein (N) and 26 non-structural proteins. There are also nine putative ORFs (ORF3a, ORF3b, ORF4, ORF5, ORF6, ORF7a, ORF7b, ORF8 and ORF10) predicted as hypothetical proteins [1].Characterization of viral mutations can provide valuable information for assessing the mechanisms linked to pathogenesis, immune evasion and viral drug resistance. In addition, viral mutation studies can be crucial for the design of new vaccines, antiviral drugs and diagnostic tests. Mutation rate of RNA viruses is dramatically higher than their hosts. This high mutation rate is correlated with virulence modulation and evolvability, which are considered beneficial for viral adaptation [2]. Tang and coworkers have recently characterized 13 variation sites in SARS-CoV-2: ORF1ab, S, ORF3a, ORF8 and N regions, among which positions 28144 in ORF8 and 8782 in ORF1a showed a mutation rate of 30.53% and 29.47%, respectively. A previo...