In order to explore the relationship between the accumulation of flavane3ol and the expression of synthesisrelated enzymes and key genes in wine grape fruit, this study analyzed the white grape variety Chardonnay grown in Donglu of Helan Mountain with colorimetric method, high performance liquid chromatography (HPLC) and fluorescence quantitative PCR (FQPCR). The accumulation rule of flavane3ol monomer and the changes of related enzyme activities and related gene expression patterns during biosynthesis of grape fruit were studied. The results showed that: (1) during the whole fruit development period, the contents of gallic catechin (GC) and epicatechin gallate (ECG) of flavane3ol were much higher than those of catechin (CAT) and epicatechin (EC). The contents of ECG and EC increased at first and then decreased with the development of fruit, and reached the maximum at 50 days after anthesis, which were 47.69 mg/g and 42.73 mg/g, respectively, while the contents of GC and CAT decreased at first and then increased, and then decreased gradually with fruit ripening. (2) The activities of flavane3alcohol biosynthesis related enzymes PAL and ANS in grape fruits increased at first and then decreased with the development of fruit. The activities of F3H, F3′H and CHI peaked at 20 days after anthesis (June 13), and then decreased rapidly, while the activity of DFR increased at first and then decreased, increased again at 50 days after anthesis, and then decreased gradually with fruit ripening. (3) The expression of structural genes PAL and ANS related to flavane3ol biosynthesis was upregulated at first and then downregulated with the development of fruit, which was consistent with the change trend of ECG and EC contents, while the expression of F3H, F3′H and CHI was downregulated at first and then upregulated. The expression of DFR was upregulated at first, then downregulated, and then upregulated again with fruit ripening. (4) Correlation analysis showed that the activities of F3H, F3′H and ANS were positively correlated with the content of GC. The expression of F3H and F3′H genes was positively correlated with the contents of GC and CAT, and the expression of ANS and PAL genes was positively correlated with the contents of ECG and GC. It was found that the synthase and gene expression related to flavane3ol biosynthesis affected the accumulation of flavane3ol compounds in grape fruit, which further affected the sensory quality of grape wine.