Dragon fruit contains oligosaccharides, Including preb iotic ingredients, that are namely raffinose, stachyose, and fructo-oligosaccharides. The heat treatment process like jam producing can affect the functional properties of a food material. The aim of the research wereto know the effect of jam processing on chemical properties, and their preb iotic properties. Evaluation of the preb iotic properties was conducted b y in vivo method i.e. prob iotic and enterob acteria population of volunteers faecal (microflora composition), preb iotic index (PI) value and Short Chain Fatty Acid (SCFA) profile. The result showed that the processing of dragon fruit into jams decreased water content, β-sianin and dissolved particles b ut increased the Insolub le Indigestib le Fraction (IIF). The PI value of dragon fruit jam were 1.70 for white dragon jam and 1.18 for red dragon fruit. The jam processing decreased PI value up to 0.49 (red dragon fruit jam) and 0.54 (white dragon fruit jam). The fresh dragon fruit and the jam produced short chain fatty acid (SCFA) i.e. acetic and propionic acid. It can b e concluded that preb iotic properties of white dragon fruit b etter than red dragon fruit.