Purpose: Mycoplasma pneumonia is known to be a major cause of community-acquired pneumonia in children. Macrolide has been the first-line treatment for mycoplasma pneumonia, but recently there has been an increasing tendency of macrolide-resistant Mycoplasma pneumoniae (MRMP). Therefore, this study aimed to investigate the clinical tendency and the therapeutic responsibility of mycoplasma pneumonia in terms of the fever duration after treatment and its associated factors. Methods: A total of 346 children admitted with mycoplasma pneumonia during 3 recent periods (2008-2009, 2011-2012, and 2015-2016) were investigated with clinical manifestations, laboratory test results and chest x-ray findings. Patients were grouped according to fever duration and analyzed for differences in clinical features. Results: There was no statistically significant difference in age or sex between the 3 periods (P=0.284 and P=0.559, respectively). Total fever duration during mycoplasma pneumonia was increased with time (P for trend <0.001). The patients with a longer fever duration (≥3 days) after macrolide treatment presented with a higher CRP (P<0.001) and with lobar-type pneumonia (P=0.020) compared to those with a shorter fever duration. Fever duration after steroid treatment became longer in the longer fever group in 2011 (P=0.015) and 2015 (P<0.001), but not in 2008 (P=0.536). Conclusion: This study showed that the therapeutic effect of macrolide or steroid for mycoplasma pneumonia is recently attenuating and that high CRP, lobar-type pneumonia and presence of pleural effusion were the associated factors. Therefore, efforts to decrease MRMP and to develop better treatment guidelines for mycoplasma pneumonia are needed in the future. (Allergy Asthma Respir Dis 2018;6:116-121)