Today, Legionella pnuemophila is identified as usual cause of both community and nosocomial pneumonia. The PAL (peptidoglycan-associated lipoprotein) of Legionella is the most prominent surface antigen, widely conserved,species-common, immune-dominant and potentialurinary diagnostic antigen.PAL potentially elicits immune responses via the interaction with TLR2-harboring cells.Isolation, cloning and expression of PAL were aimed in this research. Pal geneof Legionella pnumophila serogroup 1, strain Paris, was amplified by PCR method,sub cloned into pET28a [+) as expression vector and sequenced in both directions. Recombinant protein after over-expression in E.coli strains BL21 (DE3) and purified by an affinity purification process with Ni+2 –nitrilotriacetic acid (NTA)-agarose. Sequencing results and western blot analysis with anti His tag,rabbit polyclonal anti-L.pneumophila antiserum and L.pneumophila-infected patient serum antibody confirmed the successful expression of recombinant PAL in the heterologous host E.coli.