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Bacillus subtilis B96-Ⅱ is a broad-spectrum biological control strain isolated from compost extracts.It could effectively suppress the soil-borne fungal diseases of vegetables.Strain B96-ⅡG13 was obtained by tagging B96-Ⅱ with the green fluorescent protein gene (gfp) for detecting colonization in asparagus.The strain B96-ⅡG13 exhibited brightly green fluorescence under a fluorescence microscope.The gfp was stable with no apparent adverse affects on the growth of wild-type strain.Asparagus plants were planted in the soil inoculated with the B96-ⅡG13.Through counting the number of colony forming units(cfu) of strain B96-ⅡG13 on selective plate culture and fluorescence microscope observation, the colonization and translocation capability of B96-ⅡG13 in asparagus plants were evaluated.The results showed B96-ⅡG13 could colonize in the asparagus root system.B96-ⅡG13 could be found from root tip to root base of the asparagus plant, and the population density showed an increasing trend from root tip to root base.In addition, B96-ⅡG13 could also be found decreased from stem base to stem top;the most population density of B96-ⅡG13 appeared in the stem base 15 days after planting.B96-ⅡG13 could still maintain certain population density from root tip to stem top 45 days after planting.Therefore, successful colonization of B.subtilis B96-ⅡG13 in asparagus root system and translocation from root to stem could be concluded.