Abstract: The cottonwood poplar, Populus deltoids, is one of the intensively cultivated species and most suitable for short-term logging in the mid-latituderegion.However, salinity, drought and low temperature seriously affected the growth and yield of this species. In this study, we isolated a PP2C clone from P. deltoids by RT-PCR, and analyzed its sequences. The open reading frame of PdPP2C is 1320 bp, coding 439 amino acids. Sequence analysis of protein indicated that the N end of PP2C protein was not highly conservative, but there was conservative protein phosphatase area in the C end. Realtime-PCR analysis revealed that this gene had been expressed in root, mature leaves, top leaves and stem, with the highest expression in the root. Adversity stress analysis showed that this gene can be expressed by inducing with NaCl, ABA and drought. Additionally, compared with the wild type, the growth of transgenic PdPP2C Arabiopsis was less inhibited by salt and drought stresses, the chlorophyll content increased, and the malondialdehyde content decreased. The above results indicate that PdPP2C as a protein phosphatase increased the resistance of Arabidopsis to various stresses.