Abstract: OBJECTIVE To explore the clinical diagnostic strategies leading to the inconsistent results between Mycoplasma pneumoniae (MP) nucleic acid testing and antibody testing， assess the values of inflammatory indicators in judgement of the status of MP infection， and observe the impact on drug therapeutic effect based on the analysis of drug resistance genes in the MP. METHODS The testing results for 1122 patients with suspected MP infection who were treated in the First Hospital of Hunan University of Chinese Medicine from Jan. 2024 to Feb. 2025 were retrospectively analyzed. The positive rates of throat swab MP-DNA and serum MP-Immunoglobulin M(IgM) were compared. The clinical manifestations of the 96 patients were observed， and the levels of inflammatory indicators procalcitonin (PCT)， C-reactive protein (CRP) and lactic dehydrogenase (LDH) were compared. Meanwhile， the drug resistance gene mutation (23S rRNA A2063G/A2064G)was tested for 150 MP-DNA-positive patients. The clinical therapeutic effects of antibiotics were compared between the drug resistant group and the non-drug resistant group. RESULTS The positive rate of throat swab MP-DNA was 13.81%， lower than 23.89% of the serum MP-IgM(P＜0.05). The CRP level of the MP-DNA-positive/IgM-negative patients was higher than that of the MP-DNA-negative /IgM-positive patients (P＜0.05)， indicating that the nucleic acid testing could better reflect the active infections. The drug resistance rate of the MP strains to macrolides was 84.67%， that is， 127 patients were in the drug resistant group， 23 patients in the non-drug resistant group. The proportion of the children was highest in the drug-resistant group(44.09%); the duration of cough and fever was longer in the drug resistant group than in the non-drug resistant group(P＜0.05)， and the effective rates of the antibiotics were reduced(48.03% vs. 82.61%，P=0.002). CONCLUSIONS The result of the nucleic acid testing should be taken as the main basis when the results of MP-DNA testing and IgM antibody testing are inconsistent， and the infection condition should be comprehensively judged with the combination of CRP level. The patients with the drug-resistant MP infection have more severe inflammatory reactions and worse therapeutic effect. Thus， the antibiotics should be used appropriately based on the result of drug resistance gene testing， and the therapeutic regimens are optimized.