To provide a method for grafting a scion to a stock in improved efficiency including the applicability to a grafting robot.

The grafting method is carried out by (1) lighting the stock 1 for ≥2 days at night before grafting work or scattering a fertilizer to the leaf surface, cutting the root and the cotyledons 2 of the stock seedling leaving one cotyledon to form a single-leaved stock and grafting the cut end of the single-leaved stock to the root-cut end 5 of a scion seedling. Another method for the grafting is carried out by (2) cutting the stalk 4 near the first true leaf 3 of the stock 1 and grafting the cut part to the cut part 5 of the root of the scion stock. The 3rd method (3) comprises the cutting of a part of the true leaf nodes 4a, 4b near the cotyledon 2 and a part near the true leaves 3a, 3b each time emerging the true leaves 3a, 3b of the stock 1 planted on the ground and the grafting of a scion 5 to the tip of the obtained true leaf nodes 4a, 4b. The grafting ratio can be improved by the method.