【Objective】 To understand of the compositional characteristics the pathogenic virus and Mycoplasma pneumoniae in acute lower respiratory infections (ALRI) children in Baoji. 【Method】 From five hospitals in Baoji City,August 2010-July 2011,7 979 cases of ALRI were collected in children hospitalized with virus and Mycoplasma pneumoniae pathogen test results for meta-analysis. 【Results】 The 7 kinds of serum acute virus IgM antibody positive rate was 32.7% in ALRI children;The positive rate were:EB virus capsid antigen antibody anti-IgM 7.6%,coxsackie virus antibody IgM 7.2%,CMV antibody IgM 5.5%,echovirus antibody IgM 5.1%,parainfluenza virus antibody IgM 4.1%,adenovirus antibody IgM 2%,respiratory syncytial virus antibody IgM 1.2%,mycoplasma pneumoniae antibody IgM positive rate 12.6%.The pathogenic nucleic acid (PCR-fluorescent probe) positive rate of lower respiratory tract secretions were:EB virus DNA 24.4%,enteric virus(ordinary type) RNA 10.7%,RSV RNA 4.3%,Coxsackie virus A16 3.8%;Mycoplasma pneumoniae nucleic acid quantitation positive rate was 11.7%.The most common clinical EBV mixed infection was with MP. 【Conclusions】 The etiology of ALRI in children shows differences in the distribution of population,area and season,year,etc.EBV and Mycoplasma pneumoniae in children with ALRI in Baoji were important pathogen.Multi-method,multi-joint detection of pathogens should be carried out.