Astilbin is a unstabledihydroflavonol anditsisomerizationand decomposition is found in neutral and weak alkaline medium. In the present study, the effects of different food components on the stability of astilbin wasstudied by HPLC. The results showed that common food additives, VC、saccharose and β-cyclodextrin (β-CD) could significantly improve its stability, while sodium benzoate has no effect. β-CD could suppress the isomerization and decomposition of astilbin through complexation; while VC and saccharose accelerate the isomerization but suppress the decomposition of astilbin. Metal ions, such as Al3+、Mg2+、Ca2+、Na+、K+could slightly improve the stability of astilbin, and Na+showed best effect. Fe3+significantly improved the decomposition of astilbin and decreasedits stability; Al3+completely inhibited the isomerization of astilbin but has no effect on its decomposition. The major components of food, protein (bovine serum albumin) and starch, have slight effects on the stability of astilbin.