Abstract:Root-knot nematode can bring serious harm to cucumber cropping in greenhouse. We found that cucumber-straw mushroom rotation cropping can effectively control the rapid rise of rook-knot nematode number and decrease the content of soil microbial biomass carbon(MBC)by cucumber-straw mushroom rotation cropping and soil treatment with alcohol solution. Soil treatment with alcohol solution has the same effect of controlling nematodes, with 2 % alcohol solution being the optimal. After the rotation and 5 days soil treatment with alcohol solution, the MBC content of 2 %, 3 % alcohol solution were higher than that of the untreated soil. 2 % alcohol treatment was the highest and then declines as time went by.