THE INVENTION RELATES TO FGF RECEPTOR-ACTIVATING N-SULFATE OLIGOSACCHARIDES HAVING FORMULA (I), WHEREIN R1, R4, R6, AND R8 ARE -OSO3- OR HYDROXYL GROUPS, R2 IS AN -O-ALKYL GROUP OR A MONOSACCHARIDE HAVING FORMULA (II), R3 IS A DISACCHARIDE HAVING FORMULA (III), R5 IS A DISACCHARIDE HAVING FORMULA (IV), R7 IS A HYDROXYL GROUP OR A DISACCHARIDE HAVING FORMULA (VI), AND R9 IS A HYDROXYL OR -O-ALKYL GROUP OR A DISACCHARIDE HAVING FORMULA (VII), WHERE R10 IS AN -O-ALKYL GROUP. THE INVENTION FURTHER RELATES TO THE PREPARATION OF SAID OLIGOSACCHARIDES AND TO THE THERAPEUTIC USE THEREOF.