Expansin is a kind of protein widely found in plants.It may relax the cell wall and plays an important role in the growth and development，and the stress response of plants.The PavEXPA2 gene was cloned and bioinformatically analyzed to uncover the structure and function of expansingene（EXPA） in sweet cherries.The gene expression in different tissues including stems，flower buds，blooming flowers，young leaves，old leaves，petioles of young leaves，petioles of old leaves，normal fruit stalks at the 2 abscission peaks and about to abscission，the normal fruits at 2 abscission peaks and shedding，and under the abiotic stresses including using 20% PEG6000 and 20 mmol/L NaCl solutions to simulate drought and salt stress for 0，2，4，6，and 8 h was profiled.The results showed that the full length of PavEXPA2 was 1 035 bp with the open reading frame （ORF） of 852 bp，encoding 283 amino acids.The putative protein has an isoelectric point of 8.90 and a molecular mass of 30.81 ku，containing two transmembrane helical structures and a signal peptide.The results of subcellular location showed that the protein of gene was located in the cell wall.The results of tissue expression analysis showed that the expression level of PavEXPA2 was higher in the easily abscised tissues of sweet cherry including flowers，stalks，fruits and petioles，with the highest level in petioles about to abscission.Compared with the samples untreated，the expression of PavEXPA2 in the drought-treated samples increased，and the expression reached the highest at 6 h，and then decreased.Under the salt stress，the expression level of PavEXPA2 decreased first，then increased and then decreased，and the expression level reached the highest at 6 h.Therefore，sweet cherries may resist stress by promoting abscission through the up-regulation of PavEXPA2 gene.It will lay a theoretical foundation for further understanding the role of PavEXPA2 in the growth and development of sweet cherries.