By comparative studies on BAF between CaCO₃-biofilter media which is a new-style filter material made of grain-slag and ceramisite filter material, the performance of phosphorus removal was discussed at different HRT and phosphorus concentrations. The results indicated that compared with ceramisite filter material, CaCO₃-biofilter media had a higher removal rate of phosphorus in BAF. Under the condition of water temperature of 20-25 ℃, ammonia nitrogen load rates of 0.76-0.78 kg·(m³·d)-1and organic load rates of 3.55-3.62 kg·(m³·d)-1, the phosphorus removals of CaCO₃-biofilter media biological aerated filter with HRT 5,3 and 1 h were in the range of 65.20％-71.07％, 40.49％-48.02％ and 26.10％-33.11％ respectively. It was evidenced that CaCO₃-biofilter media biological aerated filter could remove phosphorus effectively by biologically-induced chemical precipitation and the settling matters had no effect on the effluent turbidity.