In this study, we explored the rationality of processing methods and mechanism of Aconiti Lateralis Radix (Fuzi) through comparing the chemical contents of diester alkaloids (DAs) and monoester alkaloids (MAs) in the raw material of Fuzi and its processed products.  The results showed that the toxicity potency of MAs is at least lower than 1/64 to 1/180 of the toxicity potency of DAs.  The contents of DAs in processed Fuzi decreased to 1/76.5 to 1/38.3 of the value of raw Fuzi.  The contents of MAs in processed Fuzi significantly increased by 4.6 to 5.2 fold or basically the same as that of the raw Fuzi.  The values of MAs/DAs of processed Fuzi were enhanced by 30 to 390 fold of the raw Fuzi.  It was found that the contents of DAs were insignificantly different between “Wu dan fu pian” (steaming or stir-frying without Danba) and “Dan fu pian” (steaming or stir-frying with Danba).  The result suggested that the abilities of “eliminating toxicity” of different processing methods were equivalent at all.  In contrast, the contents of MAs contained in “Wu dan fu pian” were of 5.3 to 8.7 fold higher than the values in “Dan fu pian”.  This result suggested the processing method by steaming or stir-frying without Danba might have better effect for “conserving property” than the method processed with Danba stipulated by China Pharmacopoeia.  We believe that the new processing method without Danba can be recommended in further application due to it offers a simple procedure and it will not introduce inorganic impurities in the products.