The present invention relates to pharmaceutical compositions comprising Temozolomide or a pharmaceutically acceptable salt thereof. Said compositions comprise Temozolomide or its pharmaceutically acceptable salt and Vitamin C and/or Vitamin C derivatives. Vitamin C or Vitamin C derivatives increase the dissolution of said Temozolomide.本發明涉及一種替莫唑胺醫藥組成物,該醫藥組成物包含替莫唑胺或其藥學上可接受的鹽,以及維生素C和/或其衍生物。維生素C或其衍生物能夠保證醫藥組成物中替莫唑胺的穩定性,此外還提高了替莫唑胺的溶解性能。這有效的提高了藥物使用過程中的安全性和有效性。