OPAQUE2, encoding by gene Opaque2, is one member of alkaline leucine zipper transcription factor family, and can regulate the expressions of several related genes by combining with the promoter region. Liao2345/o2 is the gene backcross import department of o2 constructed by the laboratory. Obvious differences between protein expressions were verified by analyzing protein expressions in the endosperm of 18 days after pollination(DAP) using the method of two-dimensional electrophoresis, and 9 proteins were screened out through the mass spectrometry analysis. In order to determine the relationship between Opaque2 and the selected proteins, the amount of the RNA level expression of the selected proteins wasdetected using the relative fluorescence quantitative PCR (qRT-PCR). The result showed that Chif may be suppressed by O2, whereas Ubc, Lgl, Sdh, LOC541920, Shmt and Ppdk were likely promoted or activated by O2.