5-thioxylose compounds, especially 5-thioxylopyranose compounds, a process for their preparation, and their use for treating and/or inhibiting thromboses, especially venous thromboses. The compounds correspond to formula I: in which the pentapyranosyl group represents a free or substituted 5-thio-beta-D-xylopyranosyl group； R', R'' and R''' each independently represent a hydrogen atom, a C2-C6 acyl group, or two adjacent ones of them form a 1-methylethylidene bridge； X1 and X2 each represent carbon or nitrogen； Y1 and Y2 each independently represent carbon, nitrogen, sulfur or oxygen, with the proviso that if Y2 represents oxygen or sulfur, then Y1 represents carbon or nitrogen； R1, R2, R3, R4 and R5 each independently represent hydrogen, a COOR6 group where R6 represents hydrogen or a C1-C4 alkyl group optionally substituted by a phenyl ring, a halogen atom or a -COOR6 group； a C1-C4 alkoxy group； a C1-C6 acyl group； a benzoyl group or a phenyl ring； and the addition salts and/or active metabolites of such compounds.
