Abstract: Disclosed are a method and a system for forecasting a tree disease using moisture information. The method is carried out by a server. The method includes receiving, by the server, moisture information measured from a tree, wherein the moisture information includes a plurality of moisture information measured from the tree over time, and performing, by the server, time-series analysis of the plurality of moisture information, wherein the server performs time-series analysis of moisture information of the tree as measured over a predetermined period of time, and determines that the larger a number of inflection points of a curve corresponding to the moisture information, the higher a probability at which the tree has been infected with the tree disease.