The contents of endogenous hormones and nutrients were determined for the ovary of normal chestnut and empty\|shell chestnut.the results showed that,the contents of endogenous GA 1+3 ,iPA\-S and the ratio of (GA 1+3 +iPA\-S)/ABA in normal chestnut ovary showed as a “Double peaks” pattern,while the content of endogenous ABA in ovary tended to reversely change by a small range.In contrast,the endogenous hormone contents and their ratio in empty\|shell chestnut ovary showed no obvious peak,the contents of endogenous GA 1+3 iPA\-s and the ratio of (GA 1+3 +iPA\-S)/ABA appeared a descending trend while the endogenous ABA content appeared an ascending trend during whole embryo developmental period.The contents of reducing sugar,starch,protein,amino acids,phosphorus and potassium in empty\|shell chestnut ovary started to decline or maintained in a declining state on the 45th day after bloom(early\|July),meanwhile,those in normal chestnut ovary tended to rise up or remained high level.It is suggested that the declines of endogenous GA 1+3 ,iPA\-S contents and the ascending of endogenous ABA content lead to the low levels of reducing sugar,starch,protein,amino acids,phosphorus and potassium in ovary,which consequently cause an empty\|shell formation.
