The purpose of this study is trying to find out whether our newly developed brief version of biofeedback is an effective treatment approach for panic disorder. At the same time, the investigators want to clarify the change of bio- and psycho- indices present through the process. Patient recently experienced panic attacks are recruited in this study. The diagnosis of "Panic Disorder" is made by psychiatrists according to The Diagnostic and Statistical Manual of Mental Disorders(DSM-5) criteria. Subjects are randomly assigned to medication group or biofeedback therapy. The biofeedback therapy is conducted by psychologists following the structure way. Every subject will be measured both the bio and psycho indices on week 0, 3, and 6 under 6-week observation. In the end of the study, the investigators hope to analyze and clarify the treatment effects of our design, and also to exam the meanings of these indices, in order to find out an effective treatment approach.