Mycoplasma pneumoniae causes respiratory infections and other mucous membrane related inflammations. To explore the intra-specific variations and evolution of M. pneumoniae, a pan-genomic analysis was performed on 150 strains. In genome size evaluation of M. pneumoniae, on average 687 genes with low S.D (8.43) showed overall consistency in the gene count of 150 strains. This species is potentially pathogenic and highly evolving as 134 out of 150 showed almost all pathogenic factors with above 90% homology except 16 strains which belong to Spain, USA, China, and Japan. M. pneumoniae pan genome is an open pan genome showed total genes of 103174 in which 70359 (68.19%) core genes, 32241(31.24%) shared genes and 574 (0.55%) unique genes. Adhesin P30, Protein TopJ, ADP-ribosylating toxin CARDS toxin, GLPF, GLPK, GLPO, GLT and IgG-blocking protein M are the part of core genome. Adhesin P1, HMW1 and HMW2 genes are the part of shared genome. HMW3 and Cytadherence-associated protein P65 are the part of the unique genome in some strains. Therefore, comparative neighborhood gene analysis revealed many different neighbor genes pattern for HMW3 and P65. Phylogenetic analysis was exhibited in two main groups/clades of strains and identified major ancestral lineage within M. pneumoniae species.