Abstract: The present study aimed to investigate chemical constituents from Rosa xanthina Lindl and their effects on prothrombin time in vitro. Six compounds were obtained from the 75% ethanol extract of the fruits of R.xanthina by silica gel,Sephadex LH-20,MDS and semi-preparative HPLC technology.Based on MS,NMR spectroscopic methods,their structures were elucidated as quercetin-3-O-α-L-rhamnopyranoside (1),quercetin-3-O-(6′′-O-trans-p-coumaroyl)-β-Dglucopyranoside (2),kaempferol-4′-O-β-D-glycopyranoside (3),quercetin-4′-O-β-D-glucopyranoside (4),1,2-bis (4-hydroxy-3-methoxyphenyl)-1,3-propanediol (5),2,3-dihydroxy-1-(3-hydroxy-4-methoxyphenyl)-1-propanone (6).Compounds 1-5 were isolated from the plant for the first time,and compound 6 was isolated from this genus for the first time.Compounds (1-4) showed significant prolongation of prothrombin time comparing with control.In addition,when the concentration was higher than 27 mM,compound 1 showed significant prolongation of prothrombin time.

Key words: Rosa, Rosa xanthina Lindl, chemical constituents, prothrombin time