The present invention provides a freeze-drying method, particularly a method for freeze-drying a preparation containing ATIII. Compositions prepared by the method are also provided. Kits comprising the composition and / or lyophilized product are also provided. [Selection] Figure 1【課題】凍結乾燥方法、特にATIIIを含む製剤を凍結乾燥する方法の提供。【解決手段】その方法により調製された組成物も提供される。当該組成物及び/又は凍結乾燥製品を含むキットも提供される。【選択図】図1