Introduction: Prevalence of diabetic ulcers in Indonesia ranges from 17.3 to 32.9% of hospitalized diabetes patients. Approximately 14-24% of them cannot be healed and require amputation. Treatment of diabetic ulcers is quite difficult, because of the failure of blood vessels and bacterial infection. Merremia mammosa (Mm) (Lour.) that contains flavonoids are thought to have potential antioxidant that helps the wound healing process. This study aimed to determine the effect of Mm (Lour.) extract fractions in wound healing process of diabetic rat model and searching the most potent fraction in 25 mg effective dose. The dose was proven effective in other plant fraction and smaller dose in our preliminary study was ineffective. Method: This experimental study used twenty-five male Wistar rats that were made diabetic by intraperitoneal injection of 40 mg/kg body weight streptozotocin. Rats divided into five groups, which consist of positive control (gentamicin 0.1%), negative control (aquadest) and Mm (Lour.) dose 25 mg each of n-hexane, ethyl acetate and water fraction. Wound was made by Morton method and treatment applied on the wound every other day for 10 days. Wound healing process were observed by calculating the percentage of reduction in wound size. Data were described and analyzed further using appropriate statistic tools. Results : The percentage of reduction in wound size comparison at day 11 of the excision showed n-hexane fraction group has 90,1% , ethyl acetate fraction group has 88,5% water fraction group has 93,4%, positive control group has 92,2% and negative control grup has 81,8%. It showed significant different in every fraction when compared with negative control and no significant different when compared with positive control. This study showed that among the three factions, water fraction showed the fastest healing rate (93.4 %). Conclusion: Mm (Lour.) extract fractions significantly accelerated the process of wound healing in diabetic rat model and the most effective fraction was water fraction. Therefore, it is potential to be developed further as a topical drug.