Abstract: 【Objective】The study analyzed the berry aroma and key gene expression in normal and delayed cultivation of Summer Black grapes，which provided reference for improving the quality of grape berries in Hunan，extending the grape market time，and enhancing the techniques of grape delayed cultivation.【Method】Using nine-year-old Summer Black grape as experimental materials，a normal cultivation was set as the control group（T1）. The main shoot was pruned at the fourth node in three separate periods：May 26，2022（T2），June 5，2022（T3），and June 15，2022（T4）respec-tively. Phenological stages of different treatments were recorded，and physiological indexes of grape berries at ripening stage were measured，including single berry weight，lightness value（L^*），color index，vertical diameter，transverse diameter，hardness，total soluble solids（TSS），and total acidity（TA）contents. Gas chromatography-mass spectrometry （GC-MS）analysis was employed to detect the volatile aroma substances in the Summer Black grapes subjected to different treatments. Differences in aroma substances were analyzed，odor activity values（OAV）of the compounds were calculated，and aroma profiles were depicted. In addition，transcriptome sequencing（RNA-Seq）technology was applied to the berries from the four different delayed cultivation treatments. Differentially expressed genes（DEGs）between groups were screened using DEGSeq with the criteria of |log₂ Fold Change|≥1 and P<0.05. Expression levels of key genes involved in the methylerythritol phosphate（MEP）pathway and carotenes metabolism pathway，which regulated floral aroma and rosey aroma in Summer Black grapes，were analyzed.【Result】The results showed that，the number of days required for the T1 Summer Black grapes from budding stage to ripening stage was 30-39 d longer compared to T2，T3， and T4. The single berry weight of T1 at ripening stage（8.57 g）was significantly higher than that of T2，T3，and T4 （P<0.05，the same below）. Moreover，berries in T1 exhibited the highest TSS content，significantly higher than T2 and T4，while had no significant difference compared to T3（P>0.05）. Among the four treatments，T3 had the lowest TA content，resulting in a solid-acid ratio ranking as T3>T1>T4>T2. A total of 25，25，24，and 24 aroma substances were detected in the berries of T1，T2，T3，and T4 respectively. Ethyl acetate，hexanal，（E）-2-hexen-1-al，propionic anhydride and phenylethyl alcohol were identified as the dominant compounds，whose contents accounting for over 95% of the total compounds. Notably，terpenes content in berries in T3 were relatively abundant. Isopentyl acetate was only detected in berries in T1 and T3. Furthermore，T3 had the highest contents of nerol（16.30 μg/kg），geraniol（8.74 μg/kg）and limonene（7.31μg/kg）among four treatments. Analysis of OAV and aroma profiles revealed that 9，10，10，and 9 compounds with OAVs ≥1 were detected in T1，T2，T3，and T4 respectively. T1 exhibited the strongest intensity of fruity aroma and sweet aroma，followed by T3，with T4 having the weakest aroma intensity. RNA-Seq results revealed that 2532，781 and 1113 DEGs were up-regulated，and 1397，703 and 426 DEGs were down-regulated in T1 vs T3，T3 vs T2，and T3 vs T4 respectively. Notably，the expression levels of GPPS genes associated with terpene biosynthesis and PSY gene and CCD1 gene involved in carotene synthesis were the highest in T3 berries.【Conclusion】Summer Black whose main shoots are pruned at the fourth node on June 5 produce berries that are characterized by high sugar content and low acidity，accompanied by intense fruity aroma and floral aroma，leading to fine berry quality.