The fruit development rules of two Chinensis Actinidia cultivars were studied in this paper. ‘Fengyue’has the same fruit development cycle as‘Cuiyu’. According to soluble solids content, there are four stages during fruit development phase named comparatively stable period, slow increase period, rapid increase period and stagnating increase period. Fruit firmness change exhibits two periods, i.e. slowly declining period and rapidly declining period. There is an obvious corresponding relation between the changes of fruit firmness and the soluble solids content, i.e. the rapidly declining time of fruit firmness corresponds with the rapidly increasing time of soluble solids content. According to the experiment, the best picking periods of ‘Fengyue’and ‘Cuiyu’are mid September to mid October and early October to early November, respectively. The fruit development rules of two Chinensis Actinidia cultivars were studied in this paper. ’’ Fengyue’has the same fruit development cycle as’Cuiyu ’. According to soluble solids content, there are four stages during fruit development phase named comparatively stable period, slow increase period, rapid increase period and stagnating increase period. Fruit firmness change exhibits two periods, ie slowly declining period and rapidly declining period. There is an obvious corresponding relation between the changes of fruit firmness and the soluble solids content, ie the rapidly declining time of fruit firmness corresponds with the rapidly increasing time of soluble solids content. According to the experiment, the best picking periods of ’Fengyue’and’ Cuiyu’are mid September to mid October and early October to early November, respectively.