Objective To study the efficacy of naloxon at different doses during cardiac pulmonary cerebral resuscitation (CPCR) for prehospital cardiac arrest patients. Methods 113 patients were randomly assigned to control group (37 patients, group A), low-dose naloxon group (36 patients, group B),or high-dose naloxon group (40 patients, group C). The recovery rates of circulation and respiration, the survival rate, the rate of cerebral resuscitation, and the time to recovery of circulation and respiration were observed. Results The recovery rate of circulation was significantly higher in group C than in groups A and B (57.50% vs. 24.32% vs. 27.78%, P< 0.01). The recovery rate of respiration was markedly higher in group C than in groups A and B (52.5% vs. 18.91% vs. 22.22%, P< 0.01). The survival rate and the rate of cerebral resuscitation did not differ significantly among all the groups (P> 0.05). The time to recovery of circulation was significantly shorter in group C than in groups A and B [(10.5 ± 3. 1)m vs. (19.5 ± 3.7)m vs. (18.8 ± 3.5)m, P<0.01]. The time to recovery of respiration was shorter in group C than in groups A and B [(14.8 ± 3.9)m vs. (28.6 ± 4.5)m vs. (26.9 ± 3.7)m, P<0.01). Conclusions High-dose naloxon for prehospital cardiac arrest patients during CPCR can significantly increase the recovery rate of circulation and respiration and shorten the time to recovery of circulation and respiration. Key words: Cardiac arrest; Cardiac pulmonary cerebral resuscitation; Naloxon; Epinephrine