In order to suppress C.turgidus growth during the amplification process of filaments of S.lomentaria,the effects of five commonly used antibiotics:streptomycin(Str),ampicillin(Amp),kanamycin(Km),gentamicin(Gm)and chloramphenicol(Cm)on the growth of filaments of S.lomentaria and C.turgidus,which were co-cultured in the research were studied by experimental ecology methods in this paper.Results indicated that:(1)Str inhibited the growth of C.turgidus significantly at the concentration of 100 μg/mL,while filaments of S.lomentaria were not affected;(2)Amp and Gm had obvious inhibitory effects on the growth of C.turgidus at the concentration of 100 μg/mL,and filaments of S.lomentaria were inhibited at concentrations of 100 μg/mL and 500 μg/mL respectively;(3)The growth of the filaments of S.lomentaria was not suppressed by Km within the set range of concentration in this research,while 10 μg/mL Km inhibited C.turgidus intensively;(4)Both filaments of S.lomentaria and C.turgidus were particularly sensitive to Cm,the growth of C.turgidus was inhibited by 10 μg/mL Cm distinctly and filaments of S.lomentaria were also suppressed when the concentration of Cm reached 10 μg/mL.The results mentioned above revealed that Str(100 μg/mL),Km(100 μg/mL)and Cm(10 μg/mL)could be applied to reduce the risk of contamination of C.turgidus during the preservation and amplification of filaments of S.lomentaria.