Currently, it is important represents a serious problem in terms of public health. The goal was to make a phylogenetic analysis of bacterial β previous classifications. A phylogenetic tree of clinically important bacterial β constructed using their molecular sequences. A cladogram was made to analyze the characteristics of the families and subfamilies. The cladogram lactamases to classify the mechanisms by which bacterial resistance occurs, since it -lactamases to prepare a classification based on their molecular se analysis shows the existence of three large families of β . This work represents an advance to classify β-lactamases by their molecular sequence. quence, unlike -lactamases was -