The grafting propagation of tea plant has been thought to be worthless to practice for its difficultes. The reason why the grafting is so difficult is concluded that the tea plant has high tannin content, compact stem tissue, and delaying callus formation.But the most important factor is discovered by this investigation, it is not above-mentioned factors but the humidity.The grafting could succed with covering the scion by polyethylene bag after the operation, the most suitable season for grafting is early spring, and the best scion is the young part of tea shoot.The growth after operation is so vigorous and the flowering begins in that year or the next year. Vigorous growth is also usefull for cutting propagation.The grafting affinity between stock and scion is much or less observed.In the case of old stock, HIKATSUGI (crown grafting) may be the most reasonable method. This investigation obtained the method of tea plant grafting and it shows vigorous growth, and promotion of the flowering. It will be a very efficient technique for tea plant breeding.