Lactobacillus casei Zhang is a probiotic lactic acid bacteria strain with excellent properties screened by our research team. It is difficult to distinguish Lactobacillus casei from its relative's species by traditional methods， and the systematic classification of Lactobacillus has recently been updated， resulting in the need to reconfirm the taxonomic status of Zhang. In this study， the taxonomic status， antibiotic resistance genes， virulence genes， and environmental resistance genes of Zhang were characterized using comparative genomics， and the bacteriocin gene cluster and potential probiotic genes carried on the genome of this strain were explored. The comparative genome's results showed that average nucleotide identity value between Zhang and Lacticaseibacillus paracasei ATCC 25302T was 98.49%. The taxonomic status of Zhang was confirmed as Lacticaseibacillus paracasei by comparison with taxonomic database and phylogenetic analysis. Zhang's genome does not contain antibiotic resistance genes， virulence genes， or environmental resistance genes. Carnocin-related bacteriocin gene cluster include core peptide， LanT transport and guided cleavage， and immune or transport functions were annotated on Zhang's genome. In addition， Zhang's genome encodes potential probiotic genes such as glutathione synthesis， riboflavin synthesis， adhesion factors， and exopolysaccharides secreted. This study updated the taxonomic status of Zhang as Lacticaseibacillus paracasei， revealed that it does not contain antibiotic resistance genes， virulence genes， or environmental resistance genes， and annotated several potential probiotic genes， providing data reference for further development and industrialization of this strain.