Aegle marmelos Correa is a plant in the form of a tree that is included in Rutacea family. It has a local name of Maja (Java). This plant is used as a traditional medicine. In Java, this plant grows in dry lowland. The habitat is around Mojokerto, in the area that was used to be Majapahit Kingdom. Several researches on Aegle marmelos Correa indicated several compounds that it contained, such as: flavonoid, alkaloid, tannin, triterpen derivation, stigmasterol, aegelin, skimmiamin, and marmin. The research aimed is to know the result of isolation steroid compound of n-hexane: ethyl acetate fraction from ethanol extract 96% cortex Aegle marmelos Correa using column chromatography method and to know the maximum absorption wavelength of steroid fraction using UV-Vis spectrophotometry and to know molecular weight of resultant steroid compound isolation of the Aegle marmelos Correa cortex based on similarity index values (SI) using Gas Cromatography-Mass Spectra (GC-MS). The research used Maja that grew in Kulon Progo, Yogyakarta. The research used explorative design. Maja cortex powder was extracted maserasi with 96% ethanol.The compound contained in the exctract was then separated using gravity colum chromatography fractionation using silica gel powder GF254 as static phase and n-heksan: ethil acetate as dynamic phase with the comparison of 2:1. The compound obtained was then analyzed using thin layer chromatography, TLC Scanner, spectrofotometer UV-Vis and Gas Cromatograph-Mass Spectra (GC-MS). Isolation steroid compound of the n-hexane: ethyl acetate fraction (2: 1) from the ethanol 96% extract of Aegle marmelos Correa cortex using column chromatography method result 9 liquid fractions composed of fractions A, B, C, D, E, F, G, H , I and obtained fraction B as a pure fraction after qualitative analysis using TLC. TLC from B fraction detected using Liebermann-Burchard. The result was spot with reddish-purple colour and has Rf value 1,0 and Rf 0,95. The result isolation of Aegle marmelos Correa steroid fraction has a maximum absorption wavelength of λ 447 nm and absorbance value 0,121. Analysis using GC-MS has 3 peaks of chromatogram with similary index 93 with 9-octadecenamide which is amide group compound and has molecular weight 281 g/mol, similarity index 82 with lupeol which is a steroid group compound and has a molecular weight of 426 g/mol and similarity index 76 with 3-hexanone which is a ketone group compound used as a mobile phase in column chromatography.