Abstract: Experiments were conducted to measure the effect of Nylon fiber, fiberglass and polypropylene net ball carriers on pH, biogas production and microorganism attachment to the carrier surfaces at 30℃ temperature with two phase anaerobic fermentation. The results showed that there was a increasing trend of pH with the increase of cow manure concentration. Biogas production in reactors increased significantly by 12.5% from 5% to 7% of manure concentration and by 33.3% from 7% to 10%. Nylon fiber and fiberglass enhanced significantly biogas production when flowage fermentation of 7% manure and prophase of 10% manure fermentation. Scanning electron micrographs showed that there were more kinds and amount of microbes adhered to the surfaces of Nylon fiber than that of fiberglass and polypropylene carriers, and microbe species and combining structure seemed different on the three carries.