Abstract: Objective: Cordyceps taii is a kind of characteristic medical fungus resource in Guizhou. In this study, the decolorization process of activated carbon for water- and alkali-extracted polysaccharides from C. taii was explored. Methods: Based on the single factor experiment of active carbon dosage, decolorization time, decolorization temperature and decolorization pH, the optimum decolorization processes of two kinds of polysaccharide with active carbon were optimized by four factors on three levels orthogonal experiment. Results: Optimal decolorization technology of water- and alkali-extracted polysaccharides were as follows: Active carbon dose were 1.5 and 2 g/100 mL, decolorization time were 10 and 30 min, decolorization temperature were at 50 and 70 °C, decolorization pH were at 4 and 8, respectively. Under the optimal conditions, the decolorization rate and the retention rate of water-extracted polysaccharides were 92.12%±0.45% and 73.46%±0.33%, and the decolorization rate and the retention rate of alkali-extracted polysaccharides were 75.67%±0.66% and 56.72%±0.47%, respectively. Conclusion: Active carbon adsorption had significant decolorization effect on water- and alkali-extracted polysaccharides from C. taii, and the retention rates of polysaccharides were both high. The decolorization process was simple, efficient, low cost and suitable for industrial application.