The medium-chain dialkanoate of low-calorie sugar and fatty acids which can be easily released is normally regarded as a potential candidate of gelator in structured edible oil preparation. This study focused on the synthesis, purification of mannitol dioctanoate and its utilisation in the preparation of structured edible oil. The mixture of acetone and n-hexane with a ratio of 7:3 (v/v) was used as the media of the reaction, and the ratio of octanoic acid to mannitol was 3:1 with Novozyme 435 as catalyst. Then, the mixture was fractionated via water/n-hexane extraction, and the purity reached 90%. HPLC-MS, ¹H and ¹³C NMR analysis showed it was 1, 6-di-O-octanomannitol, which is our target product. In structured vegetable oil preparation, 0.8-1.8% (w/w) addition of product can form gelation. The rheological measurements of the organogels showed G′, G″ increased during the first 2 weeks and then tended to be stable.