Budiani et al. mental stage of fruit were used for analysis of oil content and protein concentration. Sodium Dodecyl Sulphate-Polyacrylamide Gel Electrophoresis (SDS-PAGE) and two dimentional (2-D) electrophoresis were used to study and detect specific protein bands differentially expressed during fruit development. It was shown that oil synthesis was started at 17 weeks after anthesis (WAA). There was no correlation between concentrations of total protein with oil content during mesocarp development. From the SDS-PAGE, two protein of 31.0 kDa and 34.3 kDa were detected that their expression increased at the beginning and just before the period of active oil biosynthesis respectively. Further analysis with 2-D electrophoresis showed that 31.0 kDa-protein consist of two proteins, with pI 4,64 and pI 4,95, while 34.3 kDa protein is a single protein with pI 4,56. Partial amino acid sequencing data of the 31.0 kD protein showed that two polypeptides highly homologous with ht-ACCase biotin carboxylase subunit and four polypeptides homologuus with enoyl-ACP reductase, whereas 34.3 kD protein showed homology with glyceraldehyde-3 phosphate dehydrogenase.