A pharmaceutical composition comprising cyclodextrin/paclitaxel inclusion, which consists of paclitaxel, cyclodextrin and a pharmaceutically acceptable excipient, wherein the mass ratio of the paclitaxel to cyclodextrin is 1:10-150, the said cyclodextrin is hydroxylpropyl-sulfobutyl-7-β-cyclodextrin, or sulfobutylether-7-β-cyclodextrin, or their mixture the stability constant of the cyclodextrin/paclitaxel inclusion is Ka=5396M−1−1412M−1. The preparation method of the pharmaceutical composition is as follow: (a) A solution of cyclodextrin is added dropwise to a solution of paclitaxel in ethanol. (b) The resulting mixture is filtered through microporous membrane of 0.2-0.4 μm after being dissolved. (c) Ethanol is removed under reduced pressure to give a liquid inclusion which has the ethanol level of less than 2%, or alternatively water is also removed under reduced pressure, the resulting product is dried giving a solid inclusion.