muelleri Blume, known as porang, is a rich source of fiber derived from glucomannan in the tuber. Glucomannan can also be found in the bulbil (leaves tuber), which is 25-30%. Meanwhile, the production of Bulbil is relatively large, some are sold in bulk, while small ones are discarded. In this research, in order to produce a high concentration of glucomannan, the extraction temperature was optimized to use bulbil as a substitute source of glucomannan. Additionally glucomannan was extracted from bulbil using technical grade (70%) ethanol and a ratio of 1:3 (b/v) bulbil flour to ethanol. At 25, 50, and 75 °C, three different temperature ranges were used to extract the bulbil. The functional group was examined using Fourier Transform-Infra Red, and the isolated glucomannan level was examined using a spectrophotometer UV-Vis (FT-IR). The highest glucomannan level (30.20% b/b dry basis) was obtained from the extraction method using a temperature of 75 o C, which meets class II quality based on SNI 01-1680-1989. The increase in extraction temperature can reduce moisture, ash, protein, fat, and starch content but increase crude fibers and brightness. Analysis of the functional group showed that the extracted glucomannan has a spectrum similarity to commercial glucomannan. Amorphophallus muelleri Blume; bulbils; glucomannan; ethanol; temperature