A new biological nutrient removal system combining A²/O process with fixed film was developed in this work and the characteristics of phosphorus removal were especially investigated in the combined fixed film reactor(CFFR). Media was added in the anaerobic, anoxic and aerobic reactors, respectively. Tests were made to establish the effluent level of T-P, COD, pH, SS and nitrate effects on phosphorus removal in the CFFR by decreasing hydraulic retention time (HRT) from 10 to 3.5 hours and by increasing internal recycle ratio from 0% to 200%. The influent was synthesized to levels similar to the average influent of municipal wastewater treatment plants in Korea. SARAN media with a porosity of 96.3% was packed 40%/30%/25% based on its reactor volume, respectively. It was found that T-P removal efficiencies were 39.4% 20.5% as HRT decreased from 10 hours to 3.5 hours and optimum range of pH for effective phosphorus removal was 6.8∼7.7. Nitrate inhibited the P release in anaerobic reactor. As the internal recycle ratio increased from 0% to 100%, T-P removal efficiency increased in CFFR process, while T-P removal efficiency decreased at the condition of the internal recycle ratio, 200%. Further study especially on P uptake by denitrifying phosphorus removal bacteria in anoxic reactor is needed to enhance T-P removal efficiency in CFFR process.