Disclosed is a drug delivery kit, including an apparatus for preparing a drug delivery system, which includes therein a drug carrier in a gel phase or a solid phase under the airtight condition, and has therein a mixing space configured such that a drug for forming a drug delivery system with the drug carrier is injected from the outside and is mixed with the drug carrier, and a syringe for injecting the drug into the apparatus for preparing a drug delivery system. Also, an apparatus for preparing a drug delivery system, which can be applied to the drug delivery kit, and a method of preparing a drug delivery system using the apparatus are provided. The drug delivery system can be easily prepared on site, whereby the drug can be delivered in vivo.
