Abstract: This experiment was conducted to study the biochemical characters and the role of surface polymers in the trapping process of the nematode-trapping fungus, Arthrobotrys oligospora. Hyphae with traps were induced in solid medium, which were covered by dialysis-membrane. Later, hyphae with traps were incubated respectively with different solutions of five different chemicals, two enzymes and seven protease inhibitors, then their effects on trapping and killing the nematodes were studied, while the treatments to vegetative hyphae with the same solutions or chemicals were also done to determine the effects on the growth of hyphae. The results showed that 5 mol·L^-1 LiCl and pronase E can significantly reduce the trapping of the fungus to nematodes, while 0.1 mol·L^-1 NaOH, SDS-mercaptoethanol-urea PBS solution and 1.5% SDS can completely prohibit the trapping and mycelial growth. Enzyme inhibitors（except phenanthroline） had no significant impacts on the adhesion to the nematodes, while serine protease inhibitors can inhibit the killing of the fungi to the nematodes. It had no effect on the adhesion when treated nematodes with the inhibitors. The facts above confirmed that the surface polymers played a key role in the adhesion process and they were proteins or substances containing protein. It also indirectly showed the capture phase did not need protease in trapping, which involved in killing nematodes.