Abstract: Hyperthermia is applied as an adjunctive therapy with various established cancer treatments such as radiotherapy and chemotherapy. The microwave energy （ME） distributed in tumour is the determinant of hyperthermia effect. The emphasis for applicators study is how to focusing ME in center of tumour. According to the existing technology of applicators, this paper summaries the focusing techniques of both single applicator and multi-applicators array. Furthermore , the direction of development of applicator is put forward.