Senna is the sovereign ingredient of Tongbianning compound Tablet. According to established standard, content of sennoside B assessed by spectrophotometry is used to determine Senna, but the operation is complicated and sennoside B is easily disintegrated under exposure to light. In this article, methods of HPLC for determination of Aloe-emodin and Rhein are discussed in order to discover new parameters and more effective methods for Sennas analysis.