Peel of red dragon fruit is a food waste. The recent researches explain that peel of red dragon fruit had ability as natural antioxidant and coloring agent. However peel of dragon fruit also has antimicrobial activity. The objectives of this research were to determine the most appropriate solvent (ethanol-ethyl acetate combination) and extract concentration againts Staphylococcus aureus, Listeria monocytogenes, Escherichia coli, Enterobacter sp., Aspergillus flavus, and Rhizopus sp.by well diffusion method, to determine the MIC and MBC for each bacteria and to observed its stability in different pH, salt and sugar concentration, and also heating treatment. Extract was purified by using PEG 4000 and 6000 to get betalain pigment. Maceration method was done using combination of etanol and ethyl acetate (80:20) at 26oC for six hours. The optimum concentration was 10% where the inhibition againts S. aureus, L. monocytogenes, E. coli, and Enterobacter sp. were in the range of 6.83-7.88 mm, however the extract could not inhibit A. flavus and Rhizopus sp. The extract stable at range pH 4-8, salt concentration (1-4%), sugar concentration (10-40%), and heating up to 100oC for 15 minutes. Extract were identified contain saponin, alkaloid, tannin, phenolics, flavonoid, triterpenoid, steroid, and glycoside quantitatively, further more the extract contain 21.81 mg/g phenolics and 4.62 mg/g flavonoid. Moreover, extract had low level of toxicity (LC50=210.50 ppm). PEG could not separate betalain pigment with the other component.