Taxane derivatives of general formula (1) and drugs containing the same wherein at least either of X and Y is -CO-A-B (wherein A is a single bond, alkylenecarbonyl or the like, and B is optionally substituted piperidono or the like); and the other thereof is t-butoxycarbonyl or the like; and Z is H or triethylsilyl. These compounds exhibit a high solubility in water and are excellent in antitumor activity.
