Abstract: The stability of carbonic anhydrase of Pinus yunnanensis needles in different pH environment was analyzed through the test which the carbonic anhydrase in the needles of P.yunnanensis at four different ages were processed by buffers at five different pH.The results showed that carbonic anhydrase were able to maintain good stability in alkaline condition.At the same time,the stability of carbonic anhydrase of P.yunnanensis needles at different temperatures was analyzed and the results showed that carbonic anhydrase had good thermal stability at room temperature.The Orthogonal test design was adopted to research the storage stability of carbonic anhydrase.The results showed that the rules of relative activity of carbonic anhydrase changing by different storage temperatures and times were basically the same in four different ages.Among 4a,8a and 14a,the relative activity of carbonic anhydrase was the highest by the treatment combinations NO.5.Among 4a, 8a and 22a,the relative activity of carbonic anhydrase was the lowest by treatment combinations NO.16.For 4a,8a and 14a,the main factor which affected the carbonic anhydrase activity was the storage time,and for 22a,the main factor was the storage temperature.