Abstract: In order to maximize the yield of polysaccharides of Catathelasma ventricosum, response surface methodology was applied to optimize the extraction conditions (extraction temperature, ratio of water to raw material and extraction time) of polysaccharides from the fruiting bodies of Catathelasma ventricosum. A box-behnken design was used for experimental design and analysis of the results to obtain the optimal processing parameters. Among the three extraction parameters, the extraction temperature was the most significant factor to affect the yield of polysaccharides from Catathelasma ventricosum. A mathematical model with high determination coefficient was gained and could be employed to optimize polysaccharides extraction and the optimal conditions were extraction temperature 100°C, ratio of water to raw material 22.78:1, extraction time 3.66 h. Under these conditions, the experimental yield of polysaccharide was 6.47±0.14% which was close to the predicted value.