Recent experiments investigating the analgesic or anti-stress effects of electro-acupuncture provide extensive evidence that opioid or stress hormone system is involved in those effects, respectively. It has been also suggested that opioid or stress hormones modulate long-term memory consolidation or retrieval in animals and human subjects. This article reviews the possibilitythat electroacupuncture can modulate memory consolidation or retrieval. The release of serum cortisol is enhanced or reduced by high-frequency or low-frequency electroacupuncture, respectively. Also the release of beta endorphin and enkephalin is enhanced by low-frequency electroacupuncture and the release of dynorphin is enhanced by high-frequency electroacupunture. The memory consolidation is enhanced by post-training injection of Glucocorticoids, Naloxone or Dynorphin. So this review suggests strongly that memory consolidation can be modulated by electroacupuncture.