Jackfruit seeds are a source of carbohydrates, protein and energy, hence it can be used as a potential food ingredient. The purpose of this study to determine how the effect of preliminary treatment and the effect of drying temperature on the physical, chemical, and sensory jackfruit seed flour. Stages of jackfruit seed flour is that stripping the skin, slicing, soaking, blanching (without blanching , blanching and blanching with the addition of Na-metabisulphite 2000 ppm for 10 min), drying (600C, 700C, and 800C) for 2,5 hours. Furthermore, dried jackfruit seeds milled to 80 mesh size. The results showed that the highest value on bulk density and whiteness is indicated by blanching with sodium metabisulphite. Blanching is providing smaller granular granules. In sensory parameters of color, odor, and texture, blanching in sodium metabisulphite is resulting the best among the others. The higher drying temperature is resulting the lower bulk density and whiteness. At low temperatures, the granular form is more compact compared to higher temperatures. In color and aroma parameters, the drying temperature 700C is better than the others. This research is conducted by Desti Dwi Kusumawati from Department of Food Science and Technology UNS, under supervision of Ir. Bambang Sigit A, M.Si and Dimas Rahadian A.M, S.TP, M.Sc. This article is also published in Jurnal Teknosains Pangan Vol I No 1 October 2012. It also can be downloaded in fullpaper via