Objective To explore the effect of Buyanghuishensan plus hyperbaric oxygen and medicine in the treatment of delayed encephalopathy after acute carbon monoxide poisoning .Methods According to the digital t able,143 patients with delayed encephalopathy after acute carbon monoxide poisoning were randomly divided into two groups .70 patients in the control group were treated by hyperbaric oxygen and medicine ,while 73 patients in the treat-ment group were treated by Buyanghuishensan plus hyperbaric oxygen and medicine .They were treated for three months.After three months,MMSE and ADL were used to determine changes of the patients'neurological function. Results The total effective rate of the treatment group was 97.3%,which was significantly higher than 88.6%in the control group(χ2 =4.84,P<0.05).After treatment for 3 months,the MMES score of the two groups increased signif-icantly (t=3.096,4.725,all P<0.01),and that of the treatment group increased more significantly (t=2.466,P<0.05).After treatment for 3 months,the ADL score of the two groups decreased significantly (t=2.691,3.179,P<0.05 or P<0.01),and that of the treatment group decreased more significantly (t=2.607,P<0.05).Conclusion Buyanghuishensan plus hyperbaric oxygen and medicine can improve neurological function in patients with delayed encephalopathy after acute carbon monoxide poisoning .