Abstract: The ultrasonic extraction technologies of total flavonoids from roselle were optimized using response surface analysis with Box-Behnken design, and their stabilities were further studied. Results showed that, the optimum conditions for total flavonoids extraction were determined as follows: ethanol concentration of 60%, liquid-material ratio of 50∶1（mL/g）, extraction temperature of 60 ℃, extraction time of 50 min and ultrasound power of350 W. Under these conditions, the yield of total flavonoids from roselle was 3.69%. Stability detection results showed that, the total flavonoids were more stable under dark or indoor natural light condition at 30 ～60 ℃ with pH of 3.0～6.0, while the contents of total flavonoids would be obviously decreased under strong light or inappropriate p H values. Besides, the metal ions(such as K⁺, Na⁺, Zn²⁺, Ca²⁺, Ni²⁺and Mg²⁺) showed no obvious effects on the stability of total flavonoids except Cu²⁺, Fe²⁺and Al³⁺.