Abstract: To establish a better manufacture craftwork for making castor stalks based board, the pH and acidalkali buffering capacity of the castor stalks and its different parts were examined. Besides, the relationship among pH, acid alkali buffering capacity and the extracts content, ash content was analyzed with SAS software. The results showed that the pH and the buffering capacity of the castor oil plant and its different parts were different. There was some relation between them and the extracts content and ash content. Furthermore the pH and the buffering capacity changed with the extracts and ash content changed. The pH of the castor oil plant was (5.26±0.01), acidity, the acid buffering capacity was (19.5±1) and the alkali buffering capacity was (48.5±1) of the stalks. So their acid alkali character was near to the character of the wood and it was feasible to make castor stalks based with ureaformaldehyde resin.