Abstract:The total flavonoid content of Lycium was determined using sodium borohydride/chloranil （SBC）colorimetry， NaNO2-Al（NO3）3 colorimetry， and AlCl3 colorimetry. In addition， the in vitro antioxidant activity of the flavonoid extracts was compared. The results showed that SBC colorimetry exhibited good precision， stability， repeatability， and recovery rates， and its overall performance was superior to the other two methods.The choice of standard affected the measurement results. Using rutin or quercetin as the standard provided a relatively accurate reflection of the total flavonoid content in Lycium. When quercetin was used as the standard， SBC colorimetry measured the total flavonoid content in Lycium as 10.48-116.97 mg QE/g， which was 4-31 times higher than the content measured by NaNO2-Al（NO3）3 colorimetry. The content measured by AlCl3 colorimetry was relatively lower. The total flavonoid content varied significantly among different parts of Lycium. The highest content was found in the dried root of L. barbarum L. and dried L. ruthenicum， with no significant difference between the two. The total flavonoid content in fresh and dried fruit of L. barbarum L.， measured by SBC colorimetry， was 10.48 mg QE/g and 72.22 mg QE/g， respectively. In terms of in vitro antioxidant activity， the flavonoid extracts from dried L. ruthenicum and the dried root of L. barbarum L. exhibited the highest DPPH and ABTS+ radical scavenging activities. In conclusion， SBC colorimetry detected a broader range of flavonoid compounds and provided more accurate measurements of total flavonoid content in Lycium.The flavonoid content and antioxidant activity in the dried root of L. barbarum L. and dried L. ruthenicum were higher than in other samples.