Abstract: The optimum condition of clarification process of extracting solution from Radix Puerariae with chitosan was investigated using single factor experiment and orthogonal experiment with the transport rate of flavonoid and the light transmittance of extracting solution as indexes. The optimum conditions of flocculation were as follows:the clarification temperature was 60℃, the amount of chitosan with molecular weight of 400ku was0.16g/100mL (the content of chitosan per 100mL of extracting solution from Radix Puerariae) and the pH value was 5.5. Under this condition, the transport rate of flavonoid was 73.25%, and the light transmittance was97.9%. The clarification technology by chitosan had good effect on the extracting solution from Radix Puerariae, in addition, the effective component of Radix Puerariae was well preserved.