This study was undertaken to take the correct vocal technique(especially about the resonance of oral cavity). The resonance of oral and pharyngeal cavity is the principle which can vocalize well without any abnormal signs in the throat. Therefore it is important for us to understand how to use the correct resonance of oral and pharyngeal cavity. Shimadzu X-ray remote control TV system and Shimadzu magnet $nex-{alpha}$ (SMT-50CX/H) were used for checking the movements of T-M joint and diaphragmatic respiration. The results obtained were summerized as follows: 1. While opening T-M joint space like the vowel "A" [a], We should vocalize five fundamental vowel [a,e,i,o,u] with diaphragmatic respiration holded. 2. Diminuendo must be expressed by increasing a breath volume while descending a mandible gradually because we can not ascend maxilla. So we can make a delicate expression. 3. The resonance of oral cavity must be scattered by elevating the soft palatine lightly with relax of throat.