Class A betalactamases were responsible for most of the infections in the early part of 21^st century. Hence, they are the main focus in research. Our aim was to look for conserved residues in Class A betalactamases. 70 sequences were accessed from Swiss prot and subjected to multiple sequence alignment using Clustal X 2.1. Nine segments were found to be conserved. These conserved segments included the catalytic sites which were four in number. The other conserved residues may have important functions other than catalysis.