This study separated a full-length cDNA encoding phenylalnine ammonialyase （PAL） from normalized full-length cDNA library of “Nai” (Prunus salicina) and named PsPAL.We studied the bioinformation and expession profile of PsPAL.The results indicated that:(1)The full-length of cDNA sequence was 2 497 bp,which contained an open reading frame of 2 154 bp and encoded a protein of 718 amino acid residues with a calculated molecular weight of 78 kD and isoelectric point of 6.6.(2)Systematic cladogram analysis revealed that PsPAL and PaPAL from Prunus pseudocerasus could be categorized into the same cluster.All of them had conserved regions of phenylalanine ammonialyase-Histidine ammonialyase (PAL-HAL) and Phenylalanine ammonialyase (PAL).(3)PsPAL expression level was higher at the earlier stage of fruit development and reached the maximum at 50 days after flowering,then declined until fruit ripen.(4)Under different stresses,we tested the expression of PsPAL by real-time quantitative PCR.The expression of PsPAL was up-regulated by wound and low temperature treatment and down-regulated by high temperature and anoxic treatment.Interestingly,the expression mode of PsPAL was a saddle curve under ethylene treatment.