In a simulated seawater environment, urea-hydrolyzate strain ATCC11859(Bacillus pasteurii)was used to conduct microbial-induced calcium carbonate precipitation(MICP)aqueous solution tests and immersion method to reinforce sand column. The reinforcement effect of seawater environment on the microbial-induced calcium carbonate precipitation was investigated. The results of the aqueous solution experiments show that the seawater environment inhibits the final production of calcium carbonate during the MICP process. The immersion tests further show that the unconfined compressive strength of the strengthened specimens in seawater environment is lower than that in freshwater environment when specimens are reinforced for the same time. With the growth of time, the unconfined compressive strength of sand column samples in seawater environment is increasing.