This study was performed to investigate the characteristics of nutrient removal of municipal wastewater in membrane bioreactor system. Membrane bioreactor consists of four reactors such as two intermittently anaerobic tanks, the oxic tank and the sludge solubilizaion tank with an internal recycle. The hydraulic retention time (HRT) and flux were 6.5 hours and 20.4 L/m 2 ․hr (LMH), respectively. The removal efficiency of CODCr, SS, TN and TP were 94.0%, 99.3%, 99.9%, 69.9%, and 66.9%, respectively. The estimated true biomass yield, specific denitrification rate (SDNR), specific nitrification rate (SNR), specific phosphorus release rate (SPRR) and specific phosphorus uptake rate (SPUR) were 0.34 kgVSS/kgBOD․d, 0.067 mgNO3-N/mgVSS․d, 0.028 mgNH4-N/mgVSS․d, 16.0 mgP/gVSS․d and 2.1 mgP/gVSS․d, respectively. The contents of nitrogen and phosphorus of biomass were 8.9% and 3.5% on an average.