Abstract: Objective:Lactic acid bacteria harbored plasmid was isolated from Sichuan pickles and the sequence and function of plasmid was detected. Methods:The lactic acid bacteria harbored plasmid was screened by traditional microbial separation and alkaline lysis and then the strain was identified by morphological and physiological characteristics and its 16S rDNA sequence. Plasmid was digested with single restriction enzymes and the target DNA fragments were purified and sequenced. Then the whole sequence was finally elucidated by primer design and PCR cloning. Results:A strain harbored plasmids was isolated from Sichuan pickles and identified as Weissella cibaria. A large plasmid designated as pA010 was isolated from Weissella cibaria W5 and was 11630 bp in length with GC content of 34.6％. Sequence analysis indicated that the plasmid pA010 contained four known proteins,including tyrosine recombinase,replicative protein,antoxin PemI and toxin PemK. Based on tyrosine recombinase and replication protein,pA010 may belong to a theta-type replication plasmid. In addition,PemI and PemK,an Ⅱ-TA system,may have a role in the stability of the plasmid and enhance the adaptability of bacteria to the surrounding environment. Conclusion:Weissella cibaria W5 harbored plasmid and the sequence analysis of its plasmid pA010 provided a probability for construction vectors benefited to environmental stress tolerance.