This paper mainly studied isolation,identification and growth characters of protective culture strains separated from HOLDBACTM-YM-C.The results were that HOLDBACTM-YM-C was consisted with Lactobacillus parcasei ssp.paracasel and Propionibacterium freudenreichii subsp.Shermanii.The former was grown best at 30~37℃ in MRS broth and grew into log period for 4h;and the later was grown best at 30℃ in NaLa broth and grew into log period for 24h.The best temperature at which HOLDBACTM-YM-C acidify skim-milk was 40~43℃,and the milk was curded in 8~9h.