Microcystis aeruginosa was used as the experimental subject to examine the algae-lysing characteristics of algicidal bacteria R1(Lysinibacillus macroides),which was isolated and purified from Taihu fish innards, named Surf fish. The ability of algae-lysing, the degradation products, algae-lysing mechanism and active algicidal substances were studied with the measurement of chlorophyll a and the three dimensional fluorescence technology, the whole experimental process was carried out through high temperature treatment, acid and alkali treatment, dialysis treatment and HPLC separation technique. The results show that the strain R1 can remove Microcystis aeruginosa effectively. The contents of chl-a decrease from 205.11 mg/L to 35.61 mg/L in 10 days, with degradation rate of 82.64%. The degradation rate is 89.8% measured by 3-D flurescence technology in 10 d, which is similar to the result measured by measuring Chlorophyll-a. The fluorescence spectrometric analysis shows that the tryptophan increases and the humic acid decreases significantly. The main dissolved algal products are long-wave class tryptophan, which are mainly intracellular substances.The soluble alga may be hydrophobic acid. The active algae-lysing substances produced by R1 with molecular weight less than 500 da, are identified as bacteria secretion, could resist acid and be promoted in alkaline conditions. Active substance was separated from R1 crude extract by HPLC,and a further identification was necessary to be processed.