Introduction: Historically, Morocco has known many successive conquests and invasions that have induced genetic changes in its autochthons population. It’s known that blood groups are among the most polymorphic systems. The study of ABO blood groups showed that their distribution varied in different populations. The aim of this study is to analyze the diversity and genetic differentiation of ABO system in the Moroccan population. Material and methods: Data of ABO system genetic polymorphism from previous study were analyzed using statistical approaches which are the classical and the Bayesian methods. The classical approach has been used to assess genetic differentiation by adopting multivariate analysis type: PCA (Principal Component Analysis) and the index of genetic differentiation Fst. The Bayesian approach was used to assess the genetic structure of ABO system in the Moroccan population compared to other countries. Results: Within the studied Moroccan population, 10 ABO alleles and 21 genotypes were identified. The heterozygosis rate is about 0.74 and 0.72, respectively, for the expected and observed heterozygosis. PCA analysis shows that the studied population forms 4 groups. Data of genetic distances confirm the presence of Morocco within a group formed by Kuwait, Spain and Jordan with low genetic distances of 1%, 1.8% and 2%, respectively. The Bayesian analysis shows that all the countries, except Germany, present 5 genetic pools. Besides Morocco and Kuwait that have been found to present 5 genetic pools with similar frequencies. Conclusion: The Moroccan population studied exhibits similarity with the countries of the Middle East and the southwest of Europe.