It is important not only understanding the underlying psychodynamic mechanism of the somatization but also understanding the somatization as a process where biological and sociocultural factors are acting as maintaining and exaggerating the primary vague somatic symptoms. Recently, among mechanisms of the somatization biological and cognitive aspect became more important than psychodynamics. When the doctors see patients complain physical discomforts without organic foundation, they should give attention to the mechanism of symptom amplification, misinterpretation, individual cognitive characteristics and learned behavior. Psychiatric disorders which show somatic symptoms should be also evaluated. Autonomic dysfunctions linked with stress would give some clues of the mystery of the mind-body relationship.