The invention relates to FGF receptor-activating N-acyl octasaccharides having Formula (I), wherein: R1 is an O-alkyl group optionally replaced by one or more aryl or cycloalkyl groups, R2 is an OSO3&minus； or hydroxyl group, R3 is an alkyl, cycloalkyl, or alkyl-cycloalkyl group, R4 is a disaccharide having Formula (II), R6 is a disaccharide having Formula (III), and R8 is a disaccharide having Formula (IV), where R5, R7, and R9 are OSO3&minus； or hydroxyl groups. The invention further relates to the preparation of said octasaccharides and to the therapeutic use thereof.
