Objective: Our aims were to classify mycoplasma pneumoniae (MP) clinical isolated strain according to endonuclease map of the PCR-products of the MP P1 protein gene and to investigate MP epidemic state in Shenyang.Methods:The P1 protein gene fragment of MP isolated strain was amplified by using PCR method ,and its products were digested with Hea III, 1.5 % argarose gel electrophoresis.Results:Isolated strain showed the same map as MP FH standard strain.Conclusion: Clinical isolated strain of mycoplasma pneumoniae in Shenyang belongs to groupⅡ.