The powder X-ray diffraction Fourier fingerprint pattern technique was used to develop a new quantitation method for the analysis of andrographolide and dehydroandrographolide.  And the high performance liquid chromatography method was used to evaluate the quantity of andrographolide and dehydroandrographolide.  The relationship of diffraction peak intensity and content of andrographolide and dehydroandrographolide was investigated.  The powder X-ray diffraction Fourier fingerprint pattern analysis technique can be used to evaluate the quantity of andrographolide and dehydroandrographolide in the herb simultaneously.