Objective To compare the contents of alkaloid in Aconiti Kusnezoffii Radix with different degrees of processing and their effects on electrocardiogram and vagus nerve action potential in SD rats;To establish a toxicity evaluation method for Aconiti Kusnezoffii Radix and its processed products.Methods HPLC was used to determine the contents of six alkaloid components,including benzoyl neoaconitine,benzoyl aconitine,benzoyl subeaconitine,neoaconitine,subeaconitine and aconitine in Aconiti Kusnezoffii Radix and Aconiti Kusnezoffii Radix Cocta of soaking and boiled for 30 minutes,boiled for 4 h without soaking,soaking and boiled for 4 h,and soaking and boiled for 8 h.SD rats were subjected to sublingual drainage with Aconiti Kusnezoffii Radix and four types of processed products.The vagus nerve action potential and electrocardiogram of rats before and after administration were recorded,and the correlation analysis between alkaloid content and vagus nerve action potential and heart rate was conducted.Results The contents of alkaloid of the four processed products showed that the content of diester alkaloids was soaking and boiled for 30 min>boiled for 4 h without soaking>soaking and boiled for 4 h>soaking and boiled for 8 h;monoester alkaloid content:boiled for 4 h without soaking>soaking and boiled for 30 min>soaking and boiled for 4 h>soaking and boiled for 8 h.After the administration of each sample,compared with the basal discharge,the vagus nerve discharge of rats with different processed products was changed by sublingual administration,heart rate increased,the degree of arrhythmia increased,and it varied with the degree of processing;the results of correlation analysis showed that there was a significant correlation between the nerve discharge area and the contents of diester alkaloids and total alkaloids.Conclusion The action potential of the vagus nerve and electrocardiogram of rats after sublingual drainage administration can reflect the degree of numbness in the tongue,which can provide reference for the study of tongue sensation of Aconiti Kusnezoffii Radix.