Ten patients with SDAT received the ECP therapy. The examination of Hasegawa's Dementia Scale (HDS), single photor emission computed tomography (SPECT) brain imaging, and some biochemical parameters in blood and CSF were selected to evaluate the effect of ECP for SDAT. After ECP treatment, the average HDS score of the patients increased, the value of P was close to 0.05; and the cortical cerebellar ratios of SPECT brain scan, the superoxide dismutase (SOD) activity and the concentrations of somatostatin-like immunoreactivity (SLI), dynorphin AL-13 (Dyn Al-13) in blood and/or CSF were significantly elevated. The results indicated that ECP could not only improve cerebral blood flow, but also make a notable impact on biological active substances in blood and CSF. It is suggested that ECP is beneficial to SDAT patients.