PROBLEM TO BE SOLVED: To provide a grafting method capable of maintaining a bonded state of a scion and a rootstock in an appropriate state at a low cost.SOLUTION: In the state where a cut surface of a scion 10 and a cut surface of a rootstock 20 are closely adhered with each other, sheet-like thermoplastic resin films 38A,38B are allowed to face each other while the closely adhered part is laid between the films, ultrasonic welding is performed to the thermoplastic resin films 38A,38B by using an ultrasonic welder 34, by which an area around the closely adhered part is covered by the thermoplastic resin films 38A,38B. Thus, a bonded state of the scion and the rootstock is maintained in an appropriate state at a low cost.SELECTED DRAWING: Figure 1【課題】低コストで、穂木と台木の接合状態を適切な状態に維持することが可能な接ぎ木方法を提供する。【解決手段】穂木１０の切断面と台木２０の切断面とを密着させた状態で、密着させた部分を間に介在させてシート状の熱可塑性樹脂フィルム３８Ａ，３８Ｂを対向させ、熱可塑性樹脂フィルム３８Ａ，３８Ｂを超音波溶着機３４を用いて超音波溶着することで、密着させた部分の周囲を熱可塑性樹脂フィルム３８Ａ，３８Ｂで覆う。これにより、低コストで、穂木と台木の接合状態を適切な状態に維持する。【選択図】図１
