Abstract: Five common watermelon varieties in the Beijing region, namely ‘L600’ ‘Guanghui L1000’ ‘Jingmei 2K’ ‘Chaoyue Mengxiang’ and ‘Xiaotianwang’ were investigated to compare quality indicators such as soluble solids, hardness, organic acids, soluble sugars, sweetness, and vitamin C. The aim was to provide a basis for the selection of high-quality watermelon varieties in Beijing. The results indicated that different watermelon varieties exhibited certain variations in quality characteristics. Specifically, ‘Xiaotianwang’ displayed significantly higher hardness and vitamin C content than other varieties (P<0.05), whereas the soluble solids content was not differ significantly. ‘Jingmei 2K’ and ‘Chaoyue Mengxiang’ exhibited similar and highest levels of sucrose, fructose, glucose, and total sugars content, whereas ‘Xiaotianwang’ had the lowest total sugars content. Furthermore, ‘Xiaotianwang’ had significantly higher malic acid and total acid content compared to other varieties (P<0.05). ‘Chaoyue Mengxiang’ exhibited the lowest malic acid content, and its total acid content displayed significant differences only when compared to ‘Xiaotianwang’ (P<0.05). In contrast, no significant differences were observed when compared to other varieties. ‘Chaoyue Mengxiang’ had the highest sugar-acid ratio, which was not significantly different from L600 but significantly higher than other varieties (P<0.05). In conclusion, ‘Jingmei 2K’ and ‘Chaoyue Mengxiang’ exhibited higher sugar content, whereas ‘Xiaotianwang’ had higher vitamin C content. These findings provide a theoretical basis for the selection of watermelon varieties in the Beijing region.