Abstract: The work of sexual crossing and grafting in this experiment was started in 1951 between two tomato varieties: the Golden Beauty, a variety with large and yellow fruits of multiple cells, and the Livingstone Globe, a variety with small and red fruits of two cells. Grafting hybridization: A scion was taken from a young seedling of the Golden Beauty and grafted on the Livingstone Globe as the mentor. Leaves were removed from the scion as many as possible in order to force the fruits borne on the scion to feed on the plastic substances transported from the stock. Sexual hybridization: in one group, the Golden Beauty was used as the female parent, and to the pistils of its castrated flowers was applied the pollen of the Livingstone Globe used as the male parent; in another group, vise versa. The seeds harvested from the hybridized fruits of grafts and of crossed plants were propagated successively for the first generations (F1) in the year 1952. F2 plants raised from the fruits borne on each of different kinds of F1 plants were planted in the next year 1953. Observations made on the variations of the fruit character in the successive generations are summarized as follows: 1. In grafting hybridization, there is no appreciable difference between the fruit of the Golden Beauty and those of the scion which is of the same variety. And in sexual crossing, there is no variation either during the year of hybridization. 2. Vegetative hybrids F1 express segregation and according to the fruit size and colour of the plant, they can be classified into three groups: (1) Fruits large and yellow like those of the Golden Beauty, from which the scion was taken; (2) Fruits red like those of the stock, that is, the Livingstone Globe, but their size intermediate between that of the fruits of both parents; (3) Fruits red in colour like those of the stock, but large in size like those of the plant, from which the scion was taken. Sexual hybrids F1 as well as one group of vegetative hybrids F1 show uniformity, giving both to fruits red in colour and intermediate in size. The segregation of vegetative hybrids F1 indicates that we may win the effort of plant breeding by selection earlier than in the case of sexual hybrids F1. 3. Sexual and vegetative hybrids F2 express the same tendency of heredity, according to four kinds of fruit colour (red, yellow, pink, golden yellow), fruit weight and the time of ripening. 4. Sexual and vegetative hybrids are segregated in F2. Vegetative hybrids F2 express the phenomena of multiple forms more than the sexual hybrids F2, so that vegetative hybridization is much better in plant breeding by selection. 5. That hybrids are produced by grafting indicates that nutritional condition can cause a change of inheritance and produce variability, thus confirming that the acquired character is inheritable. 6. The vegetative hybridization and the sexual hybridization are phenomena of the same order; they may have a common basis of metabolism. Those hybrids having an abundant, complex and unstable character of inheritance and with the possibility of producing the phenomena of multiple kinds and types, similar to or different from the parents, are good for selection. Vegetative and sexual hybridization has the same effect on plant breeding.