N-Acyl octasaccharides that activate the FGF receptors, corresponding to formula (I):in which:- R1 represents a group O-alkyl optionally substituted with one or more alkyl or cycloalkyl groups,- R2 represents a group OSO3- or a hydroxyl group,- R3 represents an alkyl, cycloalkyl or alkyl-cycloalkyl group, and- R4 represents a disaccharide of formula (II), R6 represents a disaccharide of formula (III) and R8 represents a disaccharide of formula (IV), in which R5, R7 and R9 represent OSO3- or hydroxyl groups:Their preparation and their therapeutic use.會活化FGF受體之N-醯基八糖,其係相應於式(I):其中:- R1表示視情況被一或多個烷基或環烷基取代之基團O-烷基,- R2表示基團OSO3-或羥基,- R3表示烷基、環烷基或烷基-環烷基,且- R4表示式(II)二醣,R6表示式(III)二醣,且R8表示式(IV)二醣,其中R5、R7及R9表示OSO3-或羥基:其製備及其治療用途。