Abstract: Derivatives of taxol represented by the formula ##STR1## wherein R and R' are each H or the residue of an amino acid selected from the group consisting of alanine, leucine, isoleucine, saline, phenylalanine, proline, lysine and arginine or a group of the formula ##STR2## wherein n is an integer of 1 to 3 and R.sup.2 and R.sup.3 are each hydrogen on an alkyl radical having from one to three carbon atoms or wherein R.sup.2 and R.sup.3 together with the nitrogen atom to which they are attached form a saturated heterocyclic ring having four to five carbon atoms, with the proviso that at least one of R and R.sup.1 is not hydrogen, are provided together with pharmaceutical compositions of such derivatives. The taxol derivatives have increased water solubility as compared to taxol, and have excellent antitumor activity.