AIM: To evaluate the efficacy and safety of tablet huperzine-A (Hup) in patients with Alzheimer's disease. METHODS: Using multicenter, prospective, double-blind, parallel, placebo controlled and randomized method, 50 patients were administered orally 0.2 mg (4 tablets) Hup and 53 patients were given po 4 tablets of placebo bid for 8 wk. All patients were evaluated with Wechsler memory scale, Hasegawa dementia scale, mini-mental state examination scale, activity of daily living scale, treatment emergency symptom scale, and measured with BP, HR, ECG, EEG, ALT, AKP, BUN, Cr, Hb, WBC, and urine routine. RESULTS: About 58% (29/50) of patients treated with Hup showed improvements in their memory (P < 0.01), cognitive (P < 0.01), and behavioral (P < 0.01 functions. The efficacy of Hup was better than placebo (36%, 19/53) (P < 0.05). No severe side effect was found. CONCLUSION: Hup is a promising drug for symptomatic treatment of Alzheimer's disease.