Abstract: 【Objective】 This study aimed to investigate the change pattern of leaf water content， conventional chemical components， and organic acids in cigar tobacco leaves during the process of curing with stems， and find their interrelationships， in order to solve the problem of rapid water loss during the curing process， thereby providing technical refe-rence for improving the quality of domestic cigar tobacco leaves.【Method】 Taking Yunxue No.1 variety as the test mate-rials， three treatments during the process of curing with stems （T1：8 leaves harvested with stem，T2：6 leaves harvested with stems，T3：4 leaves harvested with stem）were set ， with conventional piece-by-piece curing as the control （CK）. The date of harvesting with stems was designated as 0 d. The leaf water content， conventional chemical components， and nonvolatile organic acid content during the process of curing cigar leaves with stems on 5， 10， 15， 20， 25， and 30 d were determined to analyze their change patterns. The effects of leaf water content on internal chemical components were exa-mined through correlation analysis and partial least squares structural equation model.【Result】 The leaf water content du-ring the process of curing with stems consistently followed the order T3>T2>T1>CK among the treatments. The slow decline period of water content in treatments of curing with stems was extended by 1-4 d compared to CK. Curing with stems accelerated the conversion of reducing sugars during the yellowing period and promoted the degradation of proteins and other substances， which was most pronounced at 5-20 d of curing. Curing with stems obviously affected the content of nonvolatile organic acids and higher fatty acids in cigar tobacco leaves， with the greatest magnitude of change observed on 5 d of drying. By the end of the drying process with stems （30 d）， the content of long-chain saturated fatty acids in tobacco leaves increased by 13.68%-24.89% compared to CK. Throughout the process of curing with stems （5-30 d）， the content of long-chain unsaturated fatty acids in T2 and T3 treatments was significantly higher than those in CK and T1 treatments （P<0.05）. Correlation analysis indicated that leaf water content showed extremely significantly positive correlations with conventional chemical components and malic acid content （P<0.01， the same below）. The partial least squares structural equation model showed that the leaf water content could extremely significantly positively affect the contents of reducing sugar， total nitrogen， and nicotine， and could influence the contents of malic acid and long-chain saturated fatty acids indirectly by regulating reducing sugar and total nitrogen.【Conclusion】 The process of curing with stems delays the withering period and water loss in tobacco leaves during the withering and yellowing periods， maintains cellular physiological metabolic activity， enhances carbohydrate metabolism， and accelerates the tricarboxylic acid cycle along with the formation and transformation of related products， thereby optimizing tobacco leaf quality.