Xanthone compounds and their use in depression resistance

The invention discloses xanthone compounds and their use in depression resistance. The xanthone compounds are compounds shown in the structural formula (I) or their pharmaceutically acceptable salts. An experiment proves that the xanthone compounds have good depression-resistant activity and a part of the xanthone compounds have depression-resistant activity superior to that of venlafaxine. Therefore, the xanthone compounds and their pharmaceutically acceptable salts can be used for preparation of depression-resistant drugs.