To elucidate the mechanisms underlying fruit growth and development in Chinese gooseberry (Actinidia chinensis Planch. cv. Monty), physiological and histological studies of seeded and hormone-induced parthenocarpic fruits were carried out. The results obtained were as follows: 1. Although non-pollination led to flower drop, treatments of 40 ppm KT-30 and 500 ppm GA_3 at anthesis induced parthenocarpic fruits. The KT-30-induced seedless fruits developed into larger fruits than the seeded ones because of the active cell division and enlargement of their cells. However, some of the GA_3-induced seedless fruits abscised from 8 weeks after anthesis and the others developed into very small fruits because of the inactive cell devision and small cell size. 2. Both seedless and seeded fruits followed double sigmoid growth curves and had the same growth cycles. This indicates that competition of nutrient absorption between seed and other parts of fruit is not the main factor of the intervening slow growth phase in stage Ⅱ and that fruit growth cycle in 'Monty' is constant irrespective of the presence or absence of seeds or hormonal treatments. However, fruit growth cycle in 'Monty was found to vary to some extent on account of the 'environmental conditions in the year, since fruit growth cycle varied year by year. 3. The young seeds collected from seeded fruits 3 and 4 weeks after anthesis showed very high auxin activities. Changes of auxin activities in KT-30-induced seedless fruits were the same as those in seeded fruits from which the seeds were removed. However, auxin activities in KT-30-inducecd seedless fruits were higher than those in the seeded fruits without seeds 6 and 8 weeks after anthesis. GA_3 -induced seedless fruits showed very low auxin activities. These results indicate that KT-30 treatment promotes auxin synthesis in young fruits and that the auxins produced promotes cell division and enlargement of cells in the fruits. 4. Development of ventral bundle was great in seeded fruits, moderate in KT-30-induced seedless fruits and very slight in GA_3 -induced seedless fruits. These results indicate that the development of ventral bl1ndle is closely associated with seed development and that in the KT-30-induced fruits it is closely related to the transportation of metabolites such as plant hormones. Development of vascular bundle in pedicel was slightly greater in KT-30-induced seedless fruits than in seeded fruits, while in GA_3-induced seedless fruits it was slight. 5. In regard to the quality of KT-30-induced seedless fruits, several problems such as morphological abnormality arose.