The concept of green extraction is present to make the active combination extraction process from plant extracts taking into consideration about the environmental aspects. Green extraction can reduce the use of energy, allowing the use of alternative solvents, and renewed natural products, and ensure extracts and products are safe and of high quality. One of green extraction methods is Ultrasound-Assisted Enzymatic Extraction (UAEE). The use of enzyme in the UAEE process help hydrolyzes plant cell walls,therefore it could facilitate bioactive compound to release more and faster. The acquisition of enzymes could be done by fermentation with Solid-State Fermentation (SSF) method as a pretreatment sample using Aspergillusniger fungus. The method used to extract flavonoids from king of bitter leaves. Flavonoids could inhibit the activity of α-Glucosidaseenzyme as it accelerates the hydrolysis of carbohydrates in digestive system, therefore it also could prevent diabetes mellitus. In this research, the extraction of king of bitter leaves uses a pretreatment method byenzymatichydrolysis and sonicationto obtain the concentration of flavonoids. Variations of fermentation incubation time and sonication temperatures are carried out to determine the highest extract yield. The concentration of flavonoids extract is tested using a UV-Visible spectrophotometer. The results of this research shows that the fermentation time for 5 days is the best time to do SSF using A.niger. Temperature 55°C gives the optimum crude extract yield up to 12.150%.Temperature 60°C is the optimum temperature for extraction of flavonoid content. Then, the highest percentage of α-glucosidase inhibition is achieved by sample that extracted under 40°C.