Abstract: Using fuzzy mathematics, the Muncipal Solid Waste(MSW) compost maturities in 10 different spaces in 27 meters static tunnel from Nangong compost plant were studied. After high temperature fermentation of 14 days, 10 spaces of MSW compost in static tunnel had different maturities: the ratios of water all fail to meet the requirements of the first ending of fermentation. Assessing EC, pH, E₄/E₆, C/N and GI as the index, 10 spaces of MSW composts all reached the primary maturities. Using fuzzy mathematics, the evaluation of MSW composts in static tunnel was that the best maturity of MSW composts in static tunnel was in the space of the sixth, which is in the 13.5～16.2 meter, and that the worst were in the spaces of the first, the ninth and the tenth, which are in the 0～2.7, 21.6～24.3 and 24.3～27 meter's of the tunnel.