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