Some of traditional Chinese medicine (TCM) contain arsenide, such as realgar. The total amount of arsenic in the TCM exceeds the limits according to related regulations. But the roles of arsenic in TCM or its side-effects depend on its species existing in those therapies, not on the total amount of arsenic. Therefore, in recent years, the analysis of arsenic in TCM focuses on the species of arsenic. The present paper combines the method of extracting chemical composition from bunge pricklyash seed and analyzing the contents and the speciation of arsenic of bunge pricklyash seed (BPS) in different habitat by atomic fluorescence spectrometry (AFS-3100). By using 0.45 microm filter membrane and mixed solvent, two different species of the decoction of BPS were extracted, named the suspended and the soluble, and by using ion-exchange resin, the soluble arsenic could be separated as As(III), As(V), MMA and DMA. The authors established the segregation analysis methods for those species. The results shows that BPS in different habitat all contain arsenic, mostly as the species of inorganic arsenic, and the contents of As(V) are higher than As(III). The lixiviating rate of arsenic is highest with the solvent of methanol-water (4/1), reaching 53.7%-62.3%. The recovery of the method was 96.0%-101.3% and the relative standard deviation was less than 2.66%. The results show that the sensitivity and reproducibility of this method were excellent, and provided theoretical basis for further development of BPS