Abstract: In this paper, the effects of adding ginseng extract with concentrations (w/v) of 0‰, 1‰, 3‰, 5‰, 8‰, and 10‰ to the culture medium on the strain characteristics and tolerance of stress cultured Lactobacillus paracasei JLUs66 were studied. The results showed that after adding different concentrations of ginseng extract, the growth rate, viable count, acid production rate and heat tolerance of Lactobacillus paracasei JLUs66 were negatively correlated with ginseng extract. However, the extracellular polysaccharide production, low temperature tolerance and bile salt tolerance increased with the increase of the ginseng extract concentration in the low concentration range. The low pH tolerance and NaCl tolerance of the strain showed a trend of increasing and then decreasing with the increase of ginseng extract concentration. Through comprehensive comparison, it could be concluded that the stress cultured Lactobacillus paracasei JLUs66 by 3‰ concentration of ginseng extrac had the best strain characteristics and the strongest tolerance.