Abstract: The firmness of table grapes is one of the main factors that determine the eating quality of grapes， which is subjected to the increasing attention of the fruit producers and breeders. Many studies have been carried out on berry firmness. For a better understanding of the grape firmness， this paper summarized the fruit firmness variation and influencing factors to promote the further study of grape fruit firmness. Firstly， the fruit firmness and measuring method were introduced. Secondly， we expounded the changes of fruit firmness in different growth periods. Various influencing factors were summarized in the end. Internal factors included fruit cell structure and special ions， and exogenous hormones and external conditions belonged to external factors.

Key words: grape, firmness, developmental stage, influencing factor, growth regulator