Abstract：We observed the histological structure of melon（Cucumis melo L.）fruit development by paraffin section method．The results indicated that the exocarp of melon was composed of epidermis，stomatal apparatus and epidermis hair．The cleavage of the exocarp cells is mainly in vertical direction to make fruit expand during young fruit growth．With fruit development，there are some substances containing xylogen filled in the spaces of epidemis cells and there is a quite thick cuticle layer formed on the surface of epidermis．Melon mesocarp can be divided into outer mesocarp including parenchyma cells and elongation cells and inner mesocarp composed of spongy tissue and vascular bundle．Mesocarp cells arrange close and the size and appearance of all cells have no big differences at the young fruit stage．The cleavage of mesocarp cell becomes slow and the cell volume is larger and larger as the fruit develops．When the fruit is maturing，the walls of some cells in the inner mesocarp break up and cells inoculate each other．The cellulose，a component of cell wall begins to dissolve，and finally，the fruit becomes soft and mature.
