To obtain the subject composition increased in solubility and stability and useful for treatment of breast cancer, osteoporosis, or the like, by including droloxifene and cyclodextrin.

This pharmaceutical composition comprises (A) droloxifene of the formula or its pharmaceutically acceptable salt and (B) a cyclodextrin, preferably β-cyclodextrin, β-cyclodextrin-sulfobutyl ether or hydroxypropyl-β- cyclodextrin. The composition is preferably a dry inclusion complex of the component A with the component B or an aqueous solution of inclusion complex of the component A with the component B and a molar ratio of components B/A in the inclusion complex is preferably (1:1) to (4:1). Drolosifene is preferably administered once to four times a day at a unit dosage of 0.25 mg to 100 mg in patients for both oral and parenteral administrations.