The dry preparation of the freezing universe that the purpose of the present invention improves already in the stability that provides a kind of influenza vaccine. I.e., the aqueous solution freezing universe that order meets following (A) ~ (C) condition is dry, and the dry preparation of the freezing universe that influenza vaccine stability obtains significant improvement is thereby made: (A) is containing (i) influenza vaccine, (ii) hydrophobicity Amino acid and (iii) spermine acid and its sour additional salt； (B) the dry preparation total amount of the universe is freezed obtained by opposite what, aforementioned (iii) ingredient system adds 20 ~ 85 weight %； And (C) constitutes aforementioned (iii) into the spermine acid divided and its ratio of sour additional salt by control, and it is adjusted to pH8 ~ 10.本發明之目的在於提供一種流行性感冒疫苗之安定性業經改善的冷凍乾燥製劑。即，令滿足下述(A)~(C)條件之水溶液冷凍乾燥，藉此製得流行性感冒疫苗安定性獲顯著改善之冷凍乾燥製劑：(A)含有(i)流行性感冒疫苗、(ii)疏水性胺基酸及(iii)精胺酸及其酸附加鹽；(B)相對於所得冷凍乾燥製劑總量，前述(iii)成分係添加20~85重量%；以及(C)藉由控制構成前述(iii)成分之精胺酸及其酸附加鹽之比例，而調整成pH8~10。
