Abstract: The fruit development of Actinidia kolmikta Maxim. was studied by means of LM and EM. The results are as follows: 1.Young embryo development: The gamogastrous which was constituted by polycarpel generally contained sixteen loculuses; Many anatropous ovules lay in axile placenta; Unitegimy had integumentary tapetum; The embryo sac is of Polygonum type. Pollen grains germinate about 2～4 hours after pollination, then pollen tube would reach ovule 120 hours later. After fertilization,the primary endosperm nucleus divides earlier than zygote . The endosperm development is of cellular type. 2.Fruit wall: It consisted of pericarp, pulp and pith. The pericarp which contained 2 to 3 layers of parenchyma cells is thin.The outer surface covered by cuticle and having sunken somata is smooth and glabrous. Most of the pulp,which is made up of parenchyma cells,is differe ntiated into two types of cells. Small type of cells contained more starch grains whose hydrolyzation is one of the causes for fruit softening. Parenchyma cells in pulp contained chloroplast and two kinds of idioblasts which differed in contents—one is ubiquitous crystal, the other is red foccule stained with safranine. The fruit core included parenchyma cell and poorly developed vascular bundl es. 3.Seed: The seed coat is alveolate on the outer surface,is hard and coupsed of two cells. The embryo is linearly and straight. The endosperm is well developed, mainly contains stored protein.