This study validated the effect of Vaseline and the vegetable hormone-added medicine that can influence the formation of new calluses on the injured part, with the subjects of natural monument trees and large old trees. The medicines can help in the treatment of the pored or injured parts and promote the formation of new callus on natural monument trees and large old trees, which can help vigorous growth activities and prevent any secondary infection by pathogens at the same time. It turned out that the Vaseline that is used for the protection of cambiums after surgical operations on the trees did not have any significant effect on the formation of calluses. However, since it was found that new calluses formed rapidly when applying the medicine using a vegetable hormone, the medicine is highly recommended for use. If further studies should determine proper medicines for the trees according to the kinds of trees and if the medicine is applied in proper concentrations to the injured part for rapid formation of calluses on the trees when the trees undergo surgical operations, it then should be helpful in preventing the sound part(s) of the trees from decay caused by secondary infection and treatment of the injured part.