Proteomic analysis of Lactobacillus plantarum could provide a theoretical basis for mechanism of manganese involved in metabolism of lactic acid bacteria. Growth of Lactobacillus plantarum DY-2 was observed under the cultivation with or without manganese， and protein expression was analyzed using iTRAQ technology. Bacteria culture were collected at 6 h and 9 h of the mid-logarithmic growth phase for proteomic analysis. Based on iTRAQ results， fifty-six intracellular proteins were identified having differential expression after 6 h with lack of manganese， and these 56 proteins include 31 up-regulated proteins and 25 down-regulated proteins. Seventy-eight intracellular proteins were identified having differential expression after 9 h with lack of manganese， while the expression level of 40 proteins was up-regulated and 38 proteins was down-regulated. Sixteen proteins were found to have significant differences at both time points. Proteins involved in the construction of ribosome were down-regulated with lack of manganese， while the up-regulated proteins were involved in DNA repair and stress response， and UspA family proteins did show significant difference in the fermentation process. GO analysis and KEGG metabolic pathway analysis revealed that manganese have a significant impact on metabolism pathway in L. plantarum， such as pyruvate and amino acid metabolism.