RING type E3 ubiquitin ligase play an important role in plant response to abiotic stress. In this study, we isolated a RING type E3 ubiquitin ligase gene PnLOG2 from Pharbitis purpurea. The gene ID was XM_019321049.1. The length of open reading frame was predicted to be 912 bp (51-992 bp)using ORF Finder. PnLOG2 encoded a protein of 303 residues with a predicted molecular weight of 34.38 kD and an isoelectric point of 5.14. Phylogenetic analysis showed that PnLOG2 gene was clustered with tomato E3 ubiquitin ligase gene. Tissue specific analysis showed that the expression levels of PnLOG2 in different tissues was detected. And the PnLOG2 was highly expressed in the old stem and new leaves. The qRTPCR data showed that the expression levels of PnLOG2 were significantly inducted by drought, salt and alkali stresses in the roots and leaves of P. purpurea. Further, ectopic expression of PnLOG2 in yeast cells enhanced the tolerance to salt and drought stresses, but decreased the tolerance to alkali stress. Therefore, we identified the function of PnLOG2 gene in response to drought, salt and alkali stresses, and provided a theoretical basis for further study RINGtype E3 ubiquitin in abiotic stress.