Abstract: Hong Guo Shen Guo (HGSG) are the fruits of Campanumoea lancifolia (Roxb.) Merr, which are mainly cultivated in Southwest China. This study was to investigate the ingredients from HGSG extracts and their α-glucosidase inhibition in vitro. The contents of polysaccharide, total flavonoids, total anthocyanins and total phenols in extracts from HGSG were measured using UV spectrophotometry. Chemical ingredients were further analyzed applying ultra-high performance liquid chromatography-time of flight-tandem mass spectrometry (UPLC-QTOF-MS). The results showed that the content of crude polysaccharide in five batches of HGSG was 27.59%~37.59%. The total flavone content of ethanol extract was 1.22%~1.77%, the total anthocyanin content was 0.90%~1.14%, and the total polyphenol content was 13.11%~18.85%. Twenty one compounds were identified from HGSG, including 10 flavonoids, 3 phenolic acids, 3 organic acids, 3 anthocyanins, 1 amino acid and 1 polyacetylene. The ethanol extract, crude polysaccharide and luteolin of HGSG exhibited potent α-glucosidase inhibitory activities with IC₅₀ values of 7.52, 37.43 and 8.03 μg/mL, respectively, which were significantly higher than that of acarbose (616.17 μg/mL). This study preliminarily defined the material basis of HGSG, and reported for the first time that HGSG had potential anti diabetes activity, which would provide a theoretical reference for the development and utilization of HGSG.